31-003 Code Vt. R. 31-000-003-X - VERMONT COMMERCIAL BUILDING ENERGY STANDARDS (CBES) AMENDMENTS

These rules are adopted under 30 V.S.A. § 53. This document shall be known and cited as the 2024 Vermont Commercial Building Energy Standard Amendments. The 2020 Vermont Commercial Building Energy Standards (First Printing: July 2020) published by International Code Council (ICC), Inc., as amended herein, are incorporated by reference and are available on the ICC website at: www.iccsafe.org

PREFACE

delete and replace Preface as follows:

Introduction

The 2024 Vermont Commercial Building Energy Standards (CBES) is based on the 2020 Vermont Commercial Building Energy Standards (CBES), which are based upon the International Energy Conservation Code (IECC) 2018 edition. The 2024 CBES also includes elements of the 2021 IECC energy efficiency requirements as well as select language updates and additional, more stringent Vermont energy efficiency requirements. The 2024 CBES also incorporates elements of ANSI/ASHRAE/IES Standard 90.1- 2019 Energy Standard for Buildings Except Low-Rise Residential Buildings.

This comprehensive energy conservation code establishes minimum regulations for energy efficient buildings using prescriptive and performance-related provisions. It is founded on broad- based principles that make possible the use of new materials and new energy efficient designs.

The International Energy Conservation Code provisions provide many benefits, among which is the model code development process that offers an international forum for energy professionals to discuss performance and prescriptive code requirements. This model code also encourages international consistency in the application of provisions.

Development

This 2024 CBES is founded on principles intended to establish provisions consistent with the scope of an energy conservation code that adequately conserves energy; provisions that do not unnecessarily increase construction costs; provisions that do not restrict the use of new materials, products or methods of construction; and provisions that do not give preferential treatment to particular types or classes of materials, products or methods of construction.

Background

The Vermont Commercial Building Energy Standards (CBES) was adopted by statute (30 V.S.A. § 53) in 2006. This code applies to all commercial buildings and residential building 4 stories or greater above grade in Vermont and took effect January 1, 2007.

Update Process

The Commercial Building Energy Standards statute requires that revisions to the CBES are made promptly after the issuance of updated standards under the International Energy Conservation Code (IECC). The Department of Public Service (PSD) is required to convene stakeholders that include mortgage lenders, builders, building designers, utility representatives, and other persons with experience and expertise prior to the adoption of a revised CBES to provide recommendations.

The 2024 CBES is based on the language in the International Energy Conservation Code (IECC) 2018 and 2021 editions and incorporates elements of ANSI/ASHRAE/IES Standard 90.1- 2019 Energy Standard for Buildings Except Low-Rise Residential Buildings. The 2024 CBES includes a new "Additional Efficiency, Renewable, and Load Management Requirements" section based on a points approach to code compliance. The addition of "points" provides builders and designers greater flexibility in complying with the CBES. The Vermont PSD held a series of code collaborative meetings in 2021 and a series of stakeholder and advisory committee meetings in 2022 to gather feedback on proposed changes to the CBES. The revisions presented in this document were modified based on input received from these meetings.

EFFECTIVE USE OF THE 2024 VERMONT COMMERCIAL BUILDING ENERGY STANDARDS

The 2024 Vermont Commercial Building Energy Standards (CBES) is a code that regulates minimum energy conservation requirements for new buildings as well as additions, alterations, renovations, and repairs to existing buildings. The 2024 CBES addresses energy conservation requirements for all aspects of energy uses in commercial construction, including heating and ventilating, lighting, water heating, and power usage for appliances and building systems.

The 2024 CBES is a design document. For example, before constructing a building, the designer must determine the minimum insulation R-values and fenestration U-factors for the building exterior envelope. The CBES sets forth minimum requirements for exterior envelope insulation, window and door U-factors and SHGC ratings, duct insulation, lighting and power efficiency, mechanical ventilation, and water distribution insulation.

Arrangement and Format of the 2024 CBES

The 2024 CBES, like other codes published by ICC, is arranged and organized to follow sequential steps that generally occur during a plan review or inspection. The 2024 CBES is divided into six different parts:

Chapters	Subjects
1-2	Scope, Administration and Definitions
3	General Requirements
4	Commercial Energy Efficiency
5	Existing Buildings
6	Referenced Standards

Italicized Terms

Selected terms set forth in Chapter 2: Definitions, are italicized where they appear in code text. Such terms are not italicized where the definition set forth in Chapter 2 does not impart the intended meaning in the use of the term. The terms selected have definitions that the user should read carefully to facilitate better understanding of the code.

The following is a chapter-by-chapter synopsis of the scope and intent of the provisions of the 2024 Vermont Commercial Building Energy Standards:

Chapter 1: Scope and Administration. This chapter contains provisions for the application, enforcement and administration of subsequent requirements of the code. In addition to establishing the scope of the code, Chapter 1 identifies which buildings and structures come under its purview. Chapter 1 is largely concerned with maintaining "due process of law" in enforcing the energy conservation criteria contained in the body of this code. Only through careful observation of the administrative provisions can the code official or other authority having jurisdiction, where one exists, reasonably expect to demonstrate that "equal protection under the law" has been provided.

Chapter 2 Definitions. Chapter 2 is the repository of the definitions of terms used in the body of the code. Codes are technical documents and every word, term and punctuation mark can impact the meaning of the code text and the intended results. The code often uses terms that have a unique meaning in the code and the code meaning can differ substantially from the ordinarily understood meaning of the term as used outside of the code.

The terms defined in Chapter 2 are deemed to be of prime importance in establishing the meaning and intent of the code text. The user of the code should be familiar with and consult this chapter because the definitions are essential to the correct interpretation of the code and the user may not be aware that a term is defined.

Where understanding of a term's definition is especially key to or necessary for understanding of a particular code provision, the term is shown in italics wherever it appears in the code. This is true only for those terms that have a meaning that is unique to the code. In other words, the generally understood meaning of a term or phrase might not be sufficient or consistent with the meaning prescribed by the code; therefore, it is essential that the code-defined meaning be known.

Guidance regarding tense, gender and plurality of defined terms as well as guidance regarding terms not defined in this code is provided.

Chapter 3 General Requirements. Chapter 3 provides interior design conditions that are used as a basis for assumptions in heating and cooling load calculations and provides basic material requirements for insulation materials and fenestration materials and provides standards for commercial mechanical ventilation and combustion safety.

Chapter 4 Commercial Energy Efficiency. Chapter 4 contains the energy-efficiency-related requirements for the design and construction of most types of commercial buildings, and residential buildings greater than three stories in height above grade. This chapter defines requirements for the portions of the building and building systems that impact energy use in new commercial construction and new residential construction greater than three stories in height and promotes the effective use of energy. The provisions within the chapter promote energy efficiency in the building envelope, the heating and cooling system and the service water heating system of the building.

Chapter 5 Existing Buildings. Chapter 5 of each set of provisions contains the technical energy efficiency requirements for existing buildings. Chapter 5 provisions address the maintenance of buildings in compliance with the code as well as how additions, alterations, repairs and changes of occupancy need to be addressed from the standpoint of energy efficiency. Specific provisions are provided for historic buildings.

Chapter 6 Referenced Standards. The code contains numerous references to standards that are used to regulate materials and methods of construction. Chapter 6 contains a comprehensive list of all standards that are referenced in the code. The standards are part of the code to the extent of the reference to the standard. Compliance with the referenced standard is necessary for compliance with this code. By providing specifically adopted standards, the construction and installation requirements necessary for compliance with the code can be readily determined. The basis for code compliance is, therefore, established and available on an equal basis to the code official, or other authority having jurisdiction, where one exists, contractor, designer and owner.

Chapter 6 is organized in a manner that makes it easy to locate specific standards. It lists all of the referenced standards, alphabetically, by acronym of the promulgating agency of the standard. Each agency's standards are then listed in either alphabetical or numeric order based upon the standard identification. The list also contains the title of the standard; the edition (date) of the standard referenced; any addenda included as part of the ICC adoption; and the section or sections of this code that reference the standard.

Marginal Markings

Solid vertical lines in the margins within the body of the code indicate a technical change from the requirements of the IECC 2015 and 2018 edition. Vermont specific additions and changes are designated through dotted lines in the margin. Deletion indicators in the form of an arrow ([RIGHT ARROW]) are provided in the margin where an entire section, paragraph, exception or table has been deleted or an item in a list of items or a table has been deleted.

Abbreviations and Notations

The following is a list of common abbreviations and units of measurement used in this code. Some of the abbreviations are for terms defined in Chapter 2. Others are terms used in various tables and text of the code.

AFUE	Annual fuel utilization efficiency
bhp	Brake horsepower (fans)
Btu	British thermal unit
Btu/h-ft 2	Btu per hour per square foot
C -factor	See Chapter 2--Definitions
CDD	Cooling degree days
cfm	Cubic feet per minute
cfm/ft 2	Cubic feet per minute per square foot
ci	Continuous insulation
COP	Coefficient of performance
DCV	Demand control ventilation
°C	Degrees Celsius
°F	Degrees Fahrenheit
DWHR	Drain water heat recovery
DX	Direct expansion
E c	Combustion efficiency
E v	Ventilation efficiency
E t	Thermal efficiency
EER	Energy efficiency ratio
EF	Energy factor
ERI	Energy Rating index
F -factor	See Chapter 2--Definitions
FDD	Fault detection and diagnostics
FEG	Fan efficiency grade
FL	Full load
ft 2	Square foot
gpm	Gallons per minute
HDD	Heating degree days
HERS	Home Energy Rating System
hp	Horsepower
HSPF	Heating seasonal performance factor
HVAC	Heating, ventilating and air conditioning
IEER	Integrated energy efficiency ratio
IPLV	Integrated Part Load Value
Kg/m 2	Kilograms per square meter
kW	Kilowatt
LPD	Light power density (lighting power allowance)
L/s	Liters per second
Ls	Liner system
m 2	square meters
MERV	Minimum efficiency reporting value
NAECA	National Appliance Energy Conservation Act
NPLV	Nonstandard Part Load Value
Pa	Pascal
PF	Projection factor
pcf	Pounds per cubic foot
PSD	Department of Public Service (Vermont)
psf	Pounds per square foot
PTAC	Packaged terminal air conditioner
PTHP	Packaged terminal heat pump
R -value	See Chapter 2--Definitions
SCOP	Sensible coefficient of performance
SEER	Seasonal energy efficiency ratio
SHGC	Solar Heat Gain Coefficient
SPVAC	Single packaged vertical air conditioner
SPVHP	Single packaged vertical heat pump
SRI	Solar reflectance index
SWHF	Service water heat recovery factor
U -factor	See Chapter 2--Definitions
VAV	Variable air volume
VRF	Variable refrigerant flow
VT	Visible transmittance
W	Watts
w.c.	Water column
w.g.	Water gauge

Add, amend, delete and replace as follows:

CHAPTER 1 ADMINISTRATION

PART 1 - SCOPE AND APPLICATION

Section C101. Scope and General Requirements.

- delete and replace - C101.1 Title:

This code shall be known as the 2024 Commercial Building Energy Standards (CBES) of Vermont and shall be cited as such. It is referred to herein as "this code."

- delete and replace - C101.2 Scope:

This code applies to commercial buildings and the buildings' sites and provides the minimum energy-efficient requirements for the design and construction, and a plan for operation and maintenance of:

1. New buildings and their systems.

2. New portions of buildings and their systems.

3. New systems and equipment in existing buildings.

4. New stand-alone equipment or building systems specifically identified in the standard that are part of industrial or manufacturing processes.

Exception:

1. Farm Structures. This code shall not apply to farm structures as defined in 24 Vermont Statutes Annotated (V.S.A.) § 4413.

2. Process applications. This code shall not apply to manufacturing or industrial processes equipment that are not identified in this standard or are integral to equipment that is not identified in the standard.

- delete and replace - C101.5 Compliance.

Residential buildings shall meet the provisions of the 2024 Vermont Residential Building Energy Standards (RBES), and Commercial buildings shall meet the provisions of the 2024 Vermont Commercial Building Energy Standards (CBES).

Section C102. Alternative Materials, Design and Methods of Construction and Equipment.

- delete and replace - C102.1 General.

The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the code official or other authority having jurisdiction finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, not less than the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety. Where the alternative material, design or method of construction is not approved, the code official or other authority having jurisdiction shall respond in writing, stating the reasons why the alternative was not approved.

delete and replace C102.1.1 Above code programs.

The code official or authority having jurisdiction shall be permitted to deem a national, state or local energy efficiency program an exceeding the energy efficiency required by this code.

Buildings approved in writing by such an energy efficiency program shall be considered to be in compliance with this code. The requirements identified as "mandatory" in Chapter 4 shall be met.

PART 2 ADMINISTRATION AND ENFORCEMENT

Section C103. Construction Documents.

- delete and replace - C103.1 General.

Where required construction documents and other supporting data shall be submitted in one or more sets with each application for a permit. The construction documents shall be prepared by a registered design professional where required by the statutes of the jurisdiction in which the project is to be constructed. Where special conditions exist, the code official or other authority having jurisdiction is authorized to require necessary construction documents to be prepared by a registered design professional.

Exception: The code official or other authority having jurisdiction is authorized to waive the requirements for construction documents or other supporting data if the code official or other authority having jurisdiction determines they are not necessary to confirm compliance with this code.

- delete and replace - C103.2 Information on construction documents.

Where required construction documents shall be drawn to scale on suitable material. Electronic media documents are permitted to be submitted where approved by the code official or other authority having jurisdiction. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include, but are not limited to, the following as applicable:

1. Energy compliance path.

2. Insulation materials and their R-values.

3. Fenestration U-factors and solar heat gain coefficients (SHGCs).

4. Area-weighted U-factor and solar heat gain coefficient (SHGC) calculations.

5. Design ambient temperatures.

6. Interior temperatures for heating and cooling modes.

7. Relative humidity setpoints.

8. Ventilation rates.

9. Mechanical system design criteria.

10. Mechanical and service water heating systems and equipment types, sizes and efficiencies.

11. Economizer description.

12. Equipment and system controls.

13. Fan motor horsepower (hp) and controls.

14. Duct sealing, duct and pipe insulation and location.

15. Lighting fixture schedule with wattage and control narrative.

16. Location of daylight zones on floor plans.

17. Air barrier and air sealing details, including the location of the air barrier, a diagram showing the building's pressure boundary in plan(s) and section(s), and a calculation of the area of the pressure boundary as specified in Section C402.4.1.3.

Mechanical equipment schedules shall be included in the submitted construction documents and shall include, but are not limited to, the following information:

1. Equipment efficiencies.

2. Fan and pump nameplate motor and brake horsepower.

3. Fan efficiency grade (FEG), where applicable.

4. Hydronic system (if applicable) supply and return water design temperatures for boilers and all terminal devices (e.g., baseboards, unit ventilators, etc.).

5. Steam system (if applicable) design pressure for boilers and all terminal devices.

Add C103.2.2 Electrification system. The construction documents shall provide details for additional electric infrastructure, including branch circuits, conduit, or pre-wiring, panel capacity, and electrical service capacity in compliance with the provisions of this code.

- delete and replace - C103.5 Retention of construction documents.

One set of approved construction documents shall be retained by the code official or other authority having jurisdiction for a period of not less than 180 days from date of completion of the permitted work, or as required by state or local laws.

- delete and replace - C103.6.2 Compliance documentation.

Energy code compliance documentation and supporting calculations shall be delivered in one document to the building owner as part of the project record documents or manuals, or as a standalone document. This document shall include the specific energy code edition utilized for compliance determination for each system, documentation demonstrating compliance with Section C303.1.3 for each fenestration product installed, and the interior lighting power compliance path, building area or space-by-space, used to calculate the lighting power allowance.

For projects complying with Item 1 of Section C401.2, the documentation shall include:

1. The envelope insulation compliance path.

2. All compliance calculations including those required by Sections C402.1.3, C403.8.1, C405.3 and C405.5.

CHAPTER 2 DEFINITIONS

Section C202. General Definitions.

add ALL-ELECTRIC BUILDING. A building that contains no combustion equipment, or plumbing for combustion equipment, installed within the building or building site.

add ANNUAL FUEL UTILIZATION EFFICIENCY (AFUE). Boiler and furnace efficiency measurement as the percentage of heating fuel that is effectively turned into usable energy (heat).

add APPLIANCE. A device or apparatus that is manufactured and designed to utilize energy and for which this code provides specific requirements.

delete and replace AUTHORITY HAVING JURISDICTION. The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative. For purposes of this code, neither the Vermont Public Service Department nor the Division of Fire Safety should be considered the authority having jurisdiction. Where there is conflict between rules adopted by the Division of Fire Safety and this code those adopted by the Division of Fire Safety have preemption over this code.

add AUTOMOBILE PARKING SPACE. A space within a building or private or public parking lot, exclusive of driveways, ramps, columns, office and work areas, for the parking of an automobile.

add BIOGAS. A mixture of hydrocarbons that is a gas at 60°F (15.5°C) and 1 atmosphere of pressure that is produced through the anaerobic digestion of organic matter.

add CARBON DIOXIDE EQUIVALENT (CO2e). A measure used to compare the impact of various greenhouse gases based on their global warming potential (GWP). CO2e approximates the warming effect of a unit mass of a given greenhouse gas relative to that of carbon dioxide (CO2).

delete and replace CLIMATE ZONE. A geographical region based on climatic criteria as specified in this code. Vermont is Climate Zone 6.

delete and replace CODE OFFICIAL. The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative. For purposes of this code, neither the Vermont Public Service Department nor the Division of Fire Safety should be considered the authority having jurisdiction. Where there is conflict between rules adopted by the Division of Fire Safety and this code those adopted by the Division of Fire Safety have preemption over this code.

add Combined Energy Efficiency Ratio (CEER). Window or room air conditioner efficiency measurement which combines the efficiency of the unit both in standby mode and in cooling mode.

add COMBUSTION EQUIPMENT. Any equipment or appliance used for space heating, service water heating, cooking, clothes drying and/or lighting that uses fuel gas or fuel oil.

delete and replace COMMERCIAL BUILDING ENERGY STANDARDS (CBES). The Vermont nonresidential Energy Code, based on the 2021 International Energy Conservation Code (IECC), but modified substantially.

add COMMERCIAL COOKING APPLIANCES. Appliances used in a commercial food service establishment for heating or cooking food, and which produce grease vapors, steam, fumes, smoke, or odors that are required to be removed through a local exhaust ventilation system. Such appliances include deep fat fryers, upright broilers, griddles, broilers, steam-jacketed kettles, hot- top ranges, under-fired broilers (charbroilers), ovens, barbecues, rotisseries, and similar appliances. For the purpose of this definition, a food service establishment shall include any building or a portion thereof used for the preparation and serving of food.

delete and replace COMPUTER ROOM. A room whose primary function is to house equipment for the processing and storage of electronic data which has a design total information technology equipment (ITE) equipment power density less than or equal to 20 watts per square foot (20 watts per 0.092 m) of conditioned area or a design total ITE equipment load less than or equal to 10 kW.

add DATA CENTER. A room or series of rooms that share data center systems, whose primary function is to house equipment for the processing and storage of electronic data and that has a design total ITE equipment power density exceeding 20 watts per square foot (20 watts per 0.092 m2) of conditioned area and a total design ITE equipment load greater than 10 kW.

add DATA CENTER SYSTEMS. HVAC systems and equipment, or portions thereof, used to provide cooling or ventilation in a data center.

delete and replace DEMAND RECIRCULATION WATER SYSTEM. A water distribution system where one or more pumps prime the service hot water piping with heated water upon a demand for hot water.

add DIRECT DIGITAL CONTROL (DDC). A type of control where controlled and monitored analog or binary data, such as temperature and contact closures, are converted to digital format for manipulation and calculations by a digital computer or microprocessor, then converted back to analog or binary form to control physical devices.

add ELECTRIC VEHICLE (EV). An automotive-type vehicle for on-road use, such as passenger automobiles, buses, trucks, vans, neighborhood electric vehicles, and electric motorcycles, primarily powered by an electric motor that draws current from a building electrical service, EVSE, a rechargeable storage battery, a fuel cell, a photovoltaic array, or another source of electric current.

add ELECTRIC VEHICLE CAPABLE SPACE (EV CAPABLE SPACE). A designated automobile parking space that is provided with all the requisite infrastructure in place within five feet to allow installation of electrical wiring and connection to power for EVSE

add ELECTRIC VEHICLE FAST CHARGER (EV FAST CHARGER). Also referred to as a Level 3 charger. An EV fast charger is an EVSE equipped with a direct-current (DC) plug for electric vehicle charging with either a CHAdeMO or SAE combined charging system (CCS) format connector. Other DC fast charging plug standards may be accepted as they are developed.

add ELECTRIC VEHICLE READY SPACE (EV READY SPACE). An automobile parking space that is provided with a branch circuit and either an outlet, junction box or receptacle, that will support an installed EVSE.

add ELECTRIC VEHICLE SUPPLY EQUIPMENT (EVSE). Equipment for plug-in power transfer including the ungrounded, grounded and equipment grounding conductors, and the electric vehicle connectors, attachment plugs, personal protection system and all other fittings, devices, power outlets or apparatus installed specifically for the purpose of transferring energy between the premises wiring and the electric vehicle.

add ELECTRIC VEHICLE SUPPLY EQUIPMENT INSTALLED SPACE (EVSE space). An automobile parking space that is provided with a dedicated EVSE connection.

add ENERGY EFFICIENCY RATIO (EER). Air handling unit measure of efficiency defined as the system output in Btu/h per watt of electrical energy input.

add ENTHALPY RECOVERY RATIO. Change in the enthalpy of the outdoor air supply divided by the difference between the outdoor air and entering exhaust air enthalpy, expressed as a percentage.

add ENVIRONMENTAL PRODUCT DECLARATION (EPD), TYPE III PRODUCT-SPECIFIC. An EPD is a document that describes the results of a life cycle assessment (LCA) for a material or product. While there are industry-specific EPDs, which average results across multiple product manufacturers, product-specific EPDs are the most thorough type of EPD. Type III, product- specific EPDs cover a single product from a manufacturer and are reviewed by a third-party entity. They conform to ISO 14025 and either EN 15804 or ISO 21930. Like all product specific EPDs, the scope must cover the product's life-cycle from cradle to gate.

add EQUIPMENT. Piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings. This definition shall also include other systems specifically regulated in this code.

add FAN, EMBEDDED. A fan that is part of a manufactured assembly where the assembly includes functions other than air movement.

add FAN ARRAY. Multiple fans in parallel between two plenum sections in an air distribution system.

delete FAN EFFICIENCY GRADE (FEG). A numerical rating identifying the fan's aerodynamic ability to convert shaft power, or impeller power in the case of a direct-driven fan, to air power.

add FAN ENERGY INDEX (FEI). The ratio of the electric input power of a reference fan to the electric input power of the actual fan as calculated in accordance with AMCA 208.

add FAN NAMEPLATE ELECTRICAL INPUT POWER. The nominal electrical input power rating stamped on a fan assembly nameplate.

add FAN SYSTEM ELECTRICAL INPUT POWER. The sum of the fan electrical power of all fans that are required to operate at fan system design conditions to supply air from the heating or cooling source to the conditioned spaces and/or return it to the source or exhaust it to the outdoors.

add FAULT DETECTION AND DIAGNOSTICS (FDD) SYSTEM. A software platform that utilizes building analytic algorithms to convert data provided by sensors and devices to automatically identify faults in building systems and provide a prioritized list of actionable resolutions to those faults based on cost or energy avoidance, comfort and maintenance impact.

delete and replace FENESTRATION. Products classified as either skylights or vertical fenestration.

Skylights. Glass or other transparent or translucent glazing material installed at a slope of less than 60 degrees (1.05 rad) from horizontal, including unit skylights, tubular daylighting devices and glazing materials in solariums, sunrooms, roofs, greenhouses and sloped walls.

Vertical fenestration. Windows that are fixed or operable, opaque doors, glazed doors, glazed block and combination opaque and glazed doors composed of glass or other transparent or translucent glazing materials and installed at a slope of not less than 60 degrees (1.05 rad) from horizontal.

add FUEL GAS. A natural gas, manufactured gas, liquified petroleum gas or a mixture of these.

add FUEL OIL. Kerosene or any hydrocarbon oil having a flash point not less than 100°F (38°C).

add GARAGE DOOR. A large door that allows a vehicle to access the building or allows a shipping truck to load or unload.

delete and replace GENERAL LIGHTING. Interior lighting that provides a substantially uniform level of illumination throughout a space.

add GLOBAL WARMING POTENTIAL (GWP). GWP is an index for estimating the relative global warming contribution of atmospheric emissions of 1 kg of a particular greenhouse gas compared to emissions of 1 kg of CO2. The following GWP values are used based on a 100-year time horizon: 1 for CO2, < 10 for pentane (e.g., C5H12), and 1430 for R-134a (CH2FCF3).

add GLOBAL WARMING POTENTIAL (GWP) INTENSITY. For the purposes of this document, GWP intensity refers to the GWP impact from materials (kg CO2e) divided by the project's total conditioned floor area in square feet (ft2).

delete and replace GREENHOUSE. A structure or a thermally isolated area of a building that maintains a specialized sunlit environment exclusively used for, and essential to, the cultivation, protection or maintenance of plants. Greenhouses are those that are erected for a period of 180 days or more.

delete and replace GROSS AREA OF EXTERIOR WALLS. The normal projection of all exterior walls, including the edge area of above grade floors, the edge area of roof insulation, and the area of all windows and doors installed therein (see "Exterior wall").

add HEATING SEASONAL PERFORMANCE FACTOR (HSPF). Heat pump heating efficiency rating measured as the ratio of heat output over the heating season (in Btu) to electricity used (in watt-hours).

delete and replace HIGH-EFFICACY LIGHT SOURCES. Non-linear medium screw- and pin- base lamps with an efficacy of not less than 65 lumens per watt; or light fixtures of not less than 65 lumens per watt. In determining the number or percent of lamps, each replaceable lamp (or light string) connected to a permanently installed lighting fixture shall count as one lamp.

delete HUMIDISTAT. A regulatory device, actuated by changes in humidity, used for automatic control of relative humidity.

add INFORMATION TECHNOLOGY EQUIPMENT (ITE). Items including computers, data storage devices, servers and network and communication equipment.

add INTEGRATED ENERGY EFFICIENCY RATIO (IEER). Integrated efficiency value of a mechanical system operating at 100%, 75%, 50%, and 25% of full load capacity designed to reflect the efficiency at different load levels.

add INTERNAL CURTAIN SYSTEM. A system consisting of movable panels of fabric or plastic film used to cover and uncover the space enclosed in a greenhouse on a daily basis.

add LARGE-DIAMETER CEILING FAN. A ceiling fan that is greater than 7 feet (2134 mm) in diameter. These fans are sometimes referred to as High-Volume, Low-Speed (HVLS) fans.

delete and replace METAL BUILDING. A complete integrated set of mutually dependent components and assemblies that form a building, which consists of a steel-framed superstructure and metal exterior cladding.

add MIXED-FUEL BUILDING. A building that contains combustion equipment or includes piping for such equipment.

delete and replace NETWORKED GUESTROOM CONTROL SYSTEM. A control system, with access from the front desk or other central location associated with a Group R-1 building, that is capable of identifying the rented and unrented status of each guestroom according to a timed schedule, and is capable of controlling HVAC in each hotel and motel guestroom separately.

delete and replace OCCUPANCY CLASSIFICATIONS. Building occupancies shall be defined by the 2021 International Building Code, which is summarized here. Discrepancies in the summary or further clarifications shall defer to the International Building Code.

Assembly Group A is the occupancy group used for buildings that are for the gathering of persons for purposes such as civic, social or religious functions; recreation, food or drink consumption or awaiting transportation.

The first occupancy group is A-1. The group is for the production and viewing of the performing arts, motion pictures, or television and radio studios admitting an audience.

The next occupancy group is A-2. The group includes assembly uses intended for food and/or drink consumption, such as: banquet halls, casino gambling areas, night-clubs, restaurants, cafeterias, taverns, and bars.

Group A-3 includes assembly uses intended for worship, recreation or amusement and other assembly uses not classified elsewhere in Group A such as: community halls, courtrooms, gymnasiums, and waiting areas in transportation terminals.

Group A-4 includes assembly uses intended for viewing of indoor sporting events and activities with spectator seating.

Group A-5 includes assembly uses intended for participation in or viewing outdoor activities.

Business Group B is the occupancy group used for office, professional or service-type transactions, including storage or records and accounts.

Educational Group E is the occupancy group used by six or more persons at any one time for educational purposes through the 12th grade.

Factory Industrial Group F is the occupancy group used for disassembling, fabricating, finishing, manufacturing, packaging, repair or processing operation that are not classified as Group H or Group S.

High-hazard Group H is the occupancy group used for manufacturing, processing, generation or storage of materials that constitute a physical or health hazard.

Institutional Group I is the occupancy group used for more than 16 persons, excluding staff, who reside on a 24-hour basis in a supervised environment and receive custodial care.

Mercantile Group M is the occupancy group used for the display and sale of merchandise, and involves stocks of goods, wares or merchandise.

Residential Group R is the occupancy group used for buildings that include sleeping rooms and are not institutional. There are four different occupancy groups within R.

The first occupancy group is R-1. This group is for transient uses like hotels, motels and boarding houses.

Group R-2 is occupancies containing sleeping units or more than two dwelling units where the occupants are primarily permanent. This includes apartments, dormitories, fraternities and sororities. It also includes vacation timeshares (with more than two units) and convents and monasteries. Boarding houses or congregate living facilities with 16 or fewer occupants go into Group R-3.

Group R-3 is for permanent occupancies that are not R-1, R-2, or R-4.

Group R-4 is for occupancies for more than five but not more than 16 persons, excluding staff, who reside on a 24-hour basis in a supervised residential environment and receive custodial care.

Storage Group S is the occupancy group used for storage that is not classified as a hazardous occupancy.

delete and replace ON-SITE RENEWABLE ENERGY. Energy from renewable energy resources harvested at the building project site.

delete and replace RENEWABLE ENERGY RESOURCES. Energy produced using a technology that relies on a resource that is being consumed at a harvest rate at or below its natural regeneration rate including, but not limited to, solar hot water, solar hot air, solar photovoltaics, wind, and hydro.

1. Methane gas and other flammable gases produced by the decay of sewage treatment plant wastes or landfill wastes and anaerobic digestion of agricultural products, byproducts, or wastes shall be considered renewable energy resources, but no form of solid waste, other than agricultural or silvicultural waste, shall be considered renewable.

2. The only portion of electricity produced by a system of generating resources that shall be considered renewable is that portion generated by a technology that qualifies as renewable.

3. The following fuels shall not be considered renewable energy supplies: coal, oil, propane, and natural gas.

4. Biomass is considered renewable.

delete and replace RESIDENTIAL BUILDING ENERGY STANDARDS (RBES). The Vermont Residential Energy Code based on the 2015 International Energy Conservation Code with 2018, 2020, and 2024 additions.

add SEASONAL ENERGY EFFICIENCY RATIO (SEER). Air conditioner efficiency rating, measured as the ratio of cooling output over a typical cooling season (in Btuh), divided by the provided electrical energy (in watt-hours).

delete and replace SEMI-CONDITIONED SPACE. An enclosed space within a building that is not a conditioned space, but is directly or indirectly mechanically heated or cooled.

add SOLAR-READY ZONE. A section of sections of the roof or building overhang designated and reserved for the future installation of a solar photovoltaic or solar thermal system.

add TESTING UNIT ENCLOSURE AREA. The area sum of all the boundary surfaces that define the dwelling unit, sleeping unit or occupiable conditioned space including top/ceiling, bottom/floor and all side walls. This does not include interior partition walls within the dwelling unit, sleeping unit, or occupiable conditioned space. Wall height shall be measured from the finished floor of the conditioned space to the finished floor or roof/ceiling air barrier above.

add THERMAL DISTRIBUTION EFFICIENCY (TDE). The resistance to changes in air heat as air is conveyed through a distance of air duct. TDE is a heat loss calculation evaluating the difference in the heat of the air between the air duct inlet and outlet caused by differences in temperatures between the air in the duct and the duct material. TDE is expressed as a percent difference between the inlet and outlet heat in the duct.

add TYPE III PRODUCT-SPECIFIC ENVIRONMENTAL PRODUCT DECLARATION (EPD). See ENVIRONMENTAL PRODUCT DECLARATION, TYPE III PRODUCT-SPECIFIC.

add VEGETATIVE ROOF. An assembly of interacting components designed to waterproof a building's top surface that includes, by design, vegetation and related landscape elements.

add VISIBLE TRANSMITTANCE, ANNUAL [VT annual]. The ratio of visible light entering the space through the fenestration product assembly to the incident visible light during the course of a year, which includes the effects of glazing material, frame, and light well or tubular conduit, and is expressed as a number between 0 and 1.

delete and replace WALL, ABOVE-GRADE. A wall associated with the building thermal envelope that is more than 15 percent above grade and is on the exterior of the building or any wall that is associated with the building thermal envelope that is not on the exterior of the building. This includes, but is not limited to, between-floor spandrels, peripheral edges of floors, roof knee walls, dormer walls, gable end walls, walls enclosing a mansard roof and skylight shafts.

CHAPTER 3 [CE]

GENERAL REQUIREMENTS

Section C303. Materials, Systems and Equipment.

- delete and replace - C303.1.2 Insulation mark installation.

Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection. For insulation materials that are installed without an observable manufacturer's R-value mark, such as blown or draped products, an insulation certificate complying with Section C303.1.1 shall be left immediately after installation by the installer, in a conspicuous location within the building, to certify the installed R-value of the insulation material.

- delete and replace -- TABLE C303.1.3(2)

TABLE C303.1.3(2)

DEFAULT OPAQUE DOOR U -FACTORS

DOOR TYPE	OPAQUE U-FACTOR
Uninsulated Metal1	1.20
Insulated Metal (Rolling)	0.90
Insulated Metal (Other)	0.60
Wood	0.50
Insulated, nonmetal edge, max 45% glazing, any glazing double pane	0.35
1. Uninsulated opaque doors are prohibited when part of the thermal envelope.

CHAPTER 4 COMMERCIAL ENERGY EFFICIENCY

Section C401. General.

- delete and replace -- C401.2 Application.

Commercial buildings shall comply with Section C401.2.1 or C401.2.2.

- delete and replace -- C401.2.1 CBES Prescriptive Compliance.

The Prescriptive Compliance option requires compliance with Sections C402 through C407. Dwelling units and sleeping units in Group R-2 buildings without systems serving multiple units shall be deemed to be in compliance, provided that they comply with Section R406 of RBES.

- delete and replace -- C401.2.2 ASHRAE 90.1.

Commercial buildings shall comply with the requirements of ANSI/ASHRAE/IESNA 90.1-2019. New buildings using ANSI/ASHRAE/IESNA 90.1-2019 compliance paths (a) or (b) (see ANSI/ASHRAE/IESNA 90.1-2019 section 4.2.1.1 New Buildings) shall comply with Section C406 in the 2024 CBES. Commercial building projects utilizing the alternative compliance path of ANSI/ASHRAE/IESNA 90.1-2019 must follow all applicable provisions listed in Section C401.2.2.1.

- add -- C401.2.2.1 Applicable provisions to Standard 90.1-2019.

1. All instances of the term building official in ASHRAE/IESNA 90.1-2019 shall be replaced with the terms code official or authority having jurisdiction.

2. ASHRAE/IESNA 90.1-2019 Section 4.2.1.1 New Buildings. Delete the equation for Performance Cost Index Target (PCI) and replace with:

PCI= [BPF x (BBUEC + BBREC)]/BBP.

- delete -- Table 4.2.1.1 Building Performance Factor (BPF) and replace with:

TABLE 4.2.1.1 Building Performance Factor (BPF)

Building Area Type a	Vermont BPF
Multifamily	0.55
Healthcare/hospital	0.46
Hotel/motel	0.43
Office	0.43
Restaurant	0.50
Retail	0.37
School	0.34
Warehouse	0.53
All Others	0.45
a. In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply

3. ASHRAE/IESNA 90.1-2019 Section 5.1.4.1 United States Locations. Delete the exception clause and replace with the following:

a. Adjustments may be made only in the following cases:

a. Winter heating design temperatures for projects either:

i. Located at an elevation of 1,500 feet or higher.

ii. Located in Caledonia, Essex or Orleans counties.

iii. Adjustments shall be made as listed in the National Climate Data Center for the specific weather station: http://www.ncdc.noaa.gov/cdo-web/.

b. As approved by the code official or authority having jurisdiction.

4. ASHRAE/IESNA 90.1-2019 Section 5 Building Envelope. All envelope requirements shall comply with the following tables in the 2024 Vermont Commercial Building Energy Standards(CBES):

i. Table C402.1(2) and Table C402.1(3), Building Envelope Requirements-- Opaque Assemblies and Elements. Any spaces that qualify as Semiheated in ASHRAE/IESNA 90.1-2019 need only comply with the Semiconditioned requirement in Table C402.1(2) and Table C402.1(3).

ii. Table C402.1(4), Building Envelope Requirements--Metal Building Assembly Descriptions.

iii. Table C402.3, Building Envelope Fenestration Maximum U-Factor and SHGC Requirements.

5. ASHRAE/IESNA 90.1-2019 Section 5.4.3 Air Leakage. Delete section in its entirety and replace with Section C402.4 Air leakage--thermal envelope of the 2024 Vermont CBES.

6. ASHRAE/IESNA 90.1-2019 Section 5.5.3.1 Roof Insulation. Delete section in its entirety and replace with Section C402.2.1 Roof assembly of the 2024 Vermont CBES.

7. ASHRAE/IESNA 90.1-2019 Section 5.5.3.3 Below-Grade Wall Insulation. Delete section in its entirety and replace with Section C402.2.3 Below-grade walls of the 2024 Vermont CBES.

8. ASHRAE/IESNA 90.1-2019 Section 5.5.3.5 Slab-on-Grade Floor Insulation. Add to the end of this section the requirements of section C402.2.6 Slabs-on-grade perimeter insulation of the 2024 Vermont CBES.

9. ASHRAE/IESNA 90.1-2019 Section 6.2 Compliance Path(s). Add new section as follows:

a. Section 6.2.3 Electric Resistance Space Heating. Building heating with electrical resistance units, including baseboard radiation, heat pump reheat coils, duct coils, boilers, domestic hot water heaters, and coils in terminal units and air systems is prohibited.

Exceptions to 6.2.3:

a. Areas, such as stairways, that are not permitted to be penetrated with piping or duct and no other method of heating is possible.

b. Replacement of existing electrical resistance unit.

c. Special conditions of occupancy or use that require electrical resistance heat to maintain health, safety or environmental conditions.

d. Limited areas where a practical application of resistance electrical heat is demonstrated (e.g., small interior space, such as a rest room, which is distant from the distribution system, hazardous material storerooms, stairwell or other means of emergency egress).

e. Domestic hot water heaters less than or equal to 7.5 kW in total unit input capacity.

f. Multifamily buildings with heating loads less than or equal to 6.0 Btu/hour/square foot at design temperature.

g. Cold-Climate Heat Pump where:

a. the full heating demand can be met with the heat pump at an outside air temperature of 5°F (-15°C).

b. the building thermal envelope shall be tested in accordance with ASTM E779 at a pressure differential of 0.3 inch water gauge (75 Pa) and deemed to comply with the provisions of Section C402.4.1 when the tested air leakage rate of the building thermal envelope is not greater than 0.15 cfm/ft (including the areas of the slab and below grade walls).

Buildings served by the City of Burlington Electric (BED) must also receive approval from BED before installing electric resistance heating equipment.

10. ASHRAE/IESNA 90.1-2019 Section 6.3.2(e) Criteria. Delete "an electric resistance heater."

11. ASHRAE/IESNA 90.1-2019 Section 6.4.3.5 Heat Pump Auxiliary Heat Control. Delete section in its entirety and replace with Section C403.4.1.1 Heat pump supplementary heat of the 2024 Vermont CBES.

12. ASHRAE/IESNA 90.1-2019 Section 6.4.3.8 Ventilation Controls for High-Occupancy Areas. Add exception (6): Ventilation needs for process loads.

13. ASHRAE/IESNA 90.1-2019 Section 6.4.3.9 Heated or Cooled Vestibules. Delete section in its entirety and replace with Section C403.4.1.4 Duct and plenum insulation and sealing of the 2024 Vermont CBES.

14. ASHRAE/IESNA 90.1-2019 Section 6.4.4.1.2 Duct and Plenum Insulation. Delete section in its entirety and replace with Section C403.11.1 Duct and plenum insulation and sealing of the 2024 Vermont CBES.

15. Add new Section 6.4.7 to ASHRAE/IESNA 90.1-2019, titled Economizer Fault Detection and Diagnostics (FDD). Insert Section C403.5.5 Economizer fault detection and diagnostics (FDD) of the 2024 Vermont CBES.

16. ASHRAE/IESNA 90.1-2019 Section 6.5.1 Economizers. Delete section in its entirety and replace with Section C403.5 Economizers of the 2023 Vermont CBES.

17. ASHRAE/IESNA 90.1-2019 Tables 6.5.6.1-1 and 6.5.6.1-2 Exhaust Air Energy Recovery Requirements for Ventilation Systems. Both tables shall be greater than or equal to 3,000 hours per year rather than 8,000 hours.

18. ASHRAE/IESNA 90.1-2019 Tables 6.5.6.1-1 and Table 6.5.6.1-2 Exhaust Air Energy Recovery Requirements, delete requirement for systems with [greater than or equal] 10% and < 20% outdoor air (second column of tables).

19. ASHRAE/IESNA 90.1-2019 Section 6.5.6.2 Heat Recovery for Service Water Heating. Add exception (3): If compliance with Section 6.5.6.2 will be detrimental to chiller operating efficiency due to conflicts with optimized chiller head pressure control.

20. ASHRAE/IESNA 90.1-2019 Section 6.7.2.4 System Commissioning. Delete section in its entirety and replace with Section C407 System Commissioning of the 2024 Vermont CBES.

21. ASHRAE/IESNA 90.1-2019 Section 7.1 General. Add new section as follows:

a. Section 7.1.1.4 Electrical Water Heating Limitation. Individual electric service water heating units shall be limited to a maximum of 7.5 kW total power input.

Exception: Instantaneous electric water heaters used to serve emergency showers and emergency eye wash stations.

22. ASHRAE/IESNA 90.1-2019 Table 7.8 Performance Requirements for Water Heating Equipment.

a. Change first row (Electric tabletop water heaters) size category to < 7.5 kW.

b. Change second row (Electric water heaters) size category to < 7.5 kW.

c. Delete entire third row for electric water heaters > 12 kW.

23. ASHRAE/IESNA 90.1-2019 Section 9 Lighting. All lighting power density (LPD) requirements shall comply with the following tables in the 2024 Vermont Commercial Building Energy Standards (CBES):

i. Table C405.3.2(1), Interior Lighting Power Allowances: Building Area Method.

ii. Table C405.3.2(2), Interior Lighting Power Allowances: Space-by-Space Method.

iii. Table C405.4.2(2), Individual Lighting Power Allowances for Building Exteriors. Note that Vermont does not have any exterior lighting zone 4 areas.

Exception: Exterior lighting zone 0 shall follow LPD requirements given by ASHRAE/IESNA 90.1-2019 Table 9.4.4-2.

24. ASHRAE/IESNA 90.1-2019 Section 9.4.1.3 Special Applications. At the end of the section add the following wording:

d. Luminaires providing means of egress illumination where the means of egress shall be illuminated at all times the room or space is occupied shall be controlled by occupancy sensors, or a signal from another building control system, that automatically reduces the lighting power by at least 50% when unoccupied for a period longer than 15 minutes.

Exceptions:

1. Means of egress illumination that does not exceed 0.02 watts per square foot of building area is exempt from this requirement.

2. Emergency lighting designated to meet Section 1008.3 of the International Building Code.

25. ASHRAE/IESNA 90.1-2019 Section 9.4.1.4 Exterior Lighting Control. Add the following requirement:

e. Exterior lighting shall be full cut off fixtures, limiting the light output to less than 10% at and below 10 degrees below the horizontal. Fixtures shall be independently certified by manufacturer as full cut off or meet the definition of a fully shielded light fixture.

26. ASHRAE/IESNA 90.1-2019 Section 9.4.4 Dwelling Units. Delete section in its entirety and replace with: Not less than 90% of the permanently installed lighting fixtures shall use lamps with an efficacy of at least 65 lm/W or have a total luminaire efficacy of at least 55 lm/W.

27. ASHRAE/IESNA 90.1-2019 Section 9.6.2 Additional Interior Lighting Power. Amend the exception in part (a) to read that the power shall not exceed 0.6 W/ft2 of such spaces instead of 0.75 W/ft2. In part (b), delete the equation for Additional Interior Lighting Power Allowance and replace with:

Additional interior lighting power allowance = 250 W + (Retail Area 1 x 0.20 W/ft2) + (Retail Area 2 x 0.20 W/ft2) + (Retail Area 3 x 0.50 W/ft2) + (Retail Area 4 x 0.90 W/ft2)

28. ASHRAE/IESNA 90.1-2019 Section 10.4 Mandatory Provisions. Add the following sections:

i. 10.4.6, Renewable energy systems, which will meet the requirements of Section C405.10 Renewable energy systems in the 2024 Vermont CBES.

ii. 10.4.7 Electric Vehicle Charging Stations, which will meet the requirements of Section C405.11 Electric Vehicle Charging Stations in the 2024 Vermont CBES.

- delete and replace -- C401.3 CBES Certificate and Affidavits.

30. V.S.A. § 53 requires certification that both the design and the construction of a commercial building is in compliance with the CBES. Copies of the CBES Certificate and Affidavits are available on the Department of Public Service website at https://publicservice.vermont.gov/energy_efficiency/cbes.

Certification shall be issued by an approved party completing and signing a certificate and affixing it permanently on a wall in the space where the space conditioning equipment is located, in the interior space where the electrical service panel is located, or in a visible location in the immediate vicinity of one of these areas. If located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label or other required labels. Copies of the signed certification documents shall be included in the construction files for the project, shall be sent to the local town clerk for recording in the land records, and shall be sent to the Vermont Public Service Department. The certificate shall include the following:

1. Compliance method

2. Thermal envelope details including:

a. R-values of insulation installed in or on ceilings, roofs, walls, foundations and slabs, 101229848 basement walls, crawl space walls and floors and ducts outside conditioned spaces.

b. U-factors and solar heat gain coefficients (SHGC) of fenestrations.

3. Results from any building envelope air leakage testing performed on the building.

4. An indication of the solar-ready zone and other requirements of Section C402.5.

Where there is more than one value for any component of the building envelope, the certificate shall indicate the area-weighted average value where available. If the area-weighted average is not available, the certificate shall list each value that applies to 10 percent or more of the total component area.

Section C402. Building Envelope Requirements.

- delete and replace -- C402.1 General.

In addition to the envelope requirements of Section C402, projects must achieve the required number of credits based on building occupancy group as outlined in Table C406.1.1 and Table C406.1.2. To achieve the required credits, envelope enhancements may be needed..

The requirements of C402 that may be affected and the corresponding C406 references are summarized in Table C402.1(1). For a full list of potential measures See Table C406.2.1 and Table C406.3.1.

Table C402.1(1): C406 MEASURES AFFECTING BUILDING ENVELOPE

ID	C406 Energy Credit Title	C402 Reference	C406 Section
E01	Envelope Performance	n/a	C406.2.1.1
E02	UA Reduction	C402.1.3	C406.2.1.2
E03	Envelope Leak Reduction	C403.3.2	C406.2.1.3
E04	Add Roof Insulation	C402.1.1	C406.2.1.4
E05	Add Wall Insulation	C402.1.1	C406.2.1.5
E06	Improve Fenestration	Table C402.3	C406.2.1.6
G03	Automated Shading	n/a	C406.3.4
G07	Building Thermal Mass	n/a	C406.3.8
C01	Insulation Embodied Carbon	n/a	C406.3.9

Building thermal envelope assemblies for buildings that are intended to comply with the code on a prescriptive basis in accordance with the compliance path described in Item 1 of Section C401.2, shall comply with the following:

1. The opaque portions of the building thermal envelope shall comply with the specific insulation requirements of Section C402.2 and the thermal requirements of either the R- value-based method of Section C402.1.1; the U-, C- and F-factor-based method of Section C402.1.2; the component performance alternative of Section C402.1.3; or the building above-grade performance alternative of Section C402.1.4. Building assemblies between conditioned and semi-conditioned spaces shall comply with the semi- conditioned requirements.

2. Fenestration in building envelope assemblies shall comply with Section C402.3.

Exception: Semi-conditioned spaces do not have fenestration requirements.

3. Air leakage of building envelope assemblies shall comply with Section C402.4. Buildings with both conditioned and semi-conditioned spaces shall independently comply with the requirements of Section C402.4.

4. Solar readiness of building envelope assemblies shall comply with Section C402.5.

Alternatively, where buildings have a vertical fenestration area or skylight area exceeding that allowed in Section C402.3, the building and building thermal envelope shall comply with Section C401.2, Item 2.

Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with Section C403.10.1.

- delete -- TABLE C402.1(1) and replace TABLE C402.1(2).

TABLE C402.1(2) CONDITIONED SPACE BUILDING ENVELOPE REQUIREMENTS -- OPAQUE ASSEMBLIES AND ELEMENTSa,b

COMPONENT		MAXIMUM OVERALL U-FACTOR				EXAMPLE ASSEMBLIES MEETING U-FACTOR REQUIREMENT
		All Other Occupancy Classifications		R-2 Occupancy Classifications		All Other Occupancy Classifications		R-2 Occupancy Classifications
Roofs
Insulation entirely above deck		U-0.022		Same as All Other [LEFT ARROW]		R-45ci		Same as All Other [LEFT ARROW]
Metal buildings		U-0.023		Same as All Other [LEFT ARROW]		R-10 + R-10 + R-32ci		Same as All Other [LEFT ARROW]
Attic and Otheri		U-0.017		U-0.020		R-60		R-49
Walls, Above grade
Massf		U-0.037		Same as All Other [LEFT ARROW]		R-25ci		Same as All Other [LEFT ARROW]
Metal Building		U-0.039		Same as All Other [LEFT ARROW]		R-13 + R-19.5ci or R-25ci		Same as All Other [LEFT ARROW]
Metal-framed		U-0.037		Same as All Other [LEFT ARROW]		R-13 + R-18.8ci or R-25ci		Same as All Other [LEFT ARROW]
Wood-framed and other		U-0.036		U-0.042		R-13 + R-16ci or R-19 + R-12ci or R- 25ci		R-13 + R-12ci or R-19 + R-8ci or R- 20ci
c Walls, Below Grade
Below-grade wall		C-0.048		Same as All Other [LEFT ARROW]		R-20ci		Same as All Other [LEFT ARROW]
Floors
d Mass		U-0.038		Same as All Other [LEFT ARROW]		R-23ci		Same as All Other [LEFT ARROW]
Joist/Framing--Metal		U-0.027		Same as All Other [LEFT ARROW]		R-38 + R-6ci		Same as All Other [LEFT ARROW]
Joist/Framing--Wood and Other		U-0.027		Same as All Other [LEFT ARROW]		R-38		Same as All Other [LEFT ARROW]
Slab-on-Grade Floors
Unheated slabs		F-0.434		Same as All Other [LEFT ARROW]		R-20 for 48" below		Same as All Other [LEFT ARROW]
e Heated slabs		F-0.433		Same as All Other [LEFT ARROW]		R-20 for 48" below + R-15 full slab		Same as All Other [LEFT ARROW]
e Heated slabs		F-0.433		Same as All Other [LEFT ARROW]		R-20 for 48" below + R-15 full slab		Same as All Other [LEFT ARROW]
Opaque Doors
Swingingg		U-0.37				N/A
Non-Swinging		N/A				R-4.75
Garage door <14% glazingh		N/A				R-10
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 4.88 kg/m, 1 pound per cubic foot = 16 kg/m. ci = Continuous insulation, NR = No Requirement, LS = Liner System. a. Where assembly U-factors, C-factors, and F-factors are established in ANSI/ASHRAE/IESNA 90.1-2019 Appendix A, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table, and provided that the construction, excluding the cladding system on walls, complies with the appropriate construction details from ANSI/ASHRAE/IESNA 90.1-2019 Appendix A. Alternatively, Table C402.1(4) for metal building assembly descriptions, Table C402.1(5) for metal building roof assembly U-factors, Table C402.1(6) for attic roofs with wood joists U-factors, Table C402.1(7) for metal building wall assembly U-factors, Table C402.1(8) for metal-framed wall assembly U-factors, and Table C402.1(9) for wood-framed wall assembly U-factors may be used in lieu of ANSI/ASHRAE/IESNA 90.1-2019 Appendix A. b. Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design. c. Where heated slabs are below grade, below-grade walls shall comply with the U-factor requirements for above- grade mass walls. d. "Mass floors" shall be in accordance with Section C402.2.3 and shall include floors weighing not less than: 1. 35 pounds per square foot of floor surface area; or 2. 25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic foot. e. Evidence of compliance with the F-factors indicated in the table for heated slabs shall be demonstrated by the application of the unheated slab F-factors and R-values derived from ASHRAE 90.1-2019 Appendix A. f. "Mass walls" shall be in accordance with Section C402.2.2 g. Swinging door U-factors shall be determined in accordance with NFRC-100. h. Garage doors having a single row of fenestration shall have an assembly U-factor less than or equal to 0.31, provided that fenestration area is not less than 14 percent and not more than 25 percent of the total door area. i. For Group R buildings, R-49 (U-0.023) for insulation in the ceiling slope

- add -- TABLE C402.1(3).

TABLE C402.1(3)

SEMI-CONDITIONED SPACE BUILDING ENVELOPE REQUIREMENTS--OPAQUE ASSEMBLIES AND ELEMENTSa,b

COMPONENT	MAXIMUM OVERALLU- FACTOR	EXAMPLE ASSEMBLIES MEETING U-FACTOR REQUIREMENT
	All Occupancy Classifications	All Occupancy Classifications
Roofs
Insulation entirely above deck	U-0.039	R-25ci
Metal buildings	U-0.037	R-19 + R-11 LS or R-25 + R-8 LS
Attic and Otheri	U-0.027	R-38
Walls, Above grade
Massf	U-0.104	R-9.5ci
Metal Building	U-0.060	R-15.8ci
Metal-framed	U-0.064	R-13 + R-7.5ci
Wood-framed and other	U-0.051	R-13 + R-7.5ci
c Walls, Below Grade
Below-grade wall	C-0.119	R-7.5ci
Floors
d Mass	U-0.064	R-12.5ci
Joist/Framing--Metal	U-0.052	R-19
Joist/Framing--Wood and Other	U-0.033	R-30
Slab-on-Grade Floors
Unheated slabs	F-0.540	R-10 for 24 in. below
e Heated slabs	F-0.860	R-15 for 24 in below
Opaque Doors
Swingingg	U-0.37	N/A
Non-Swinging	N/A	R-4.75
Garage door <14% glazingh	N/A	R-10
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 4.88 kg/m, 1 pound per cubic foot = 16 kg/m. ci = Continuous insulation, NR = No Requirement, LS = Liner System. a. Where assembly U-factors, C-factors, and F-factors are established in ANSI/ASHRAE/IESNA 90.1-2019 Appendix A, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table, and provided that the construction, excluding the cladding system on walls, complies with the appropriate construction details from ANSI/ASHRAE/IESNA 90.1-2019 Appendix A. Alternatively, Table C402.1(4) for metal building assembly descriptions, Table C402.1(5) for metal building roof assembly U-factors, Table C402.1(6) for attic roofs with wood joists U-factors, Table C402.1(7) for metal building wall assembly U-factors, Table C402.1(8) for metal-framed wall assembly U-factors, and Table C402.1(9) for wood-framed wall assembly U-factors may be used in lieu of ANSI/ASHRAE/IESNA 90.1-2019 Appendix A. b. Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design. c. Where heated slabs are below grade, below-grade walls shall comply with the U-factor requirements for above- grade mass walls. d. "Mass floors" shall be in accordance with Section C402.2.3 and shall include floors weighing not less than: 1. 35 pounds per square foot of floor surface area; or 2. 25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic foot. e. Evidence of compliance with the F-factors indicated in the table for heated slabs shall be demonstrated by the application of the unheated slab F-factors and R-values derived from ASHRAE 90.1-2019 Appendix A. f. "Mass walls" shall be in accordance with Section C402.2.2 g. Swinging door U-factors shall be determined in accordance with NFRC-100. h. Garage doors having a single row of fenestration shall have an assembly U-factor less than or equal to 0.36, provided that fenestration area is not less than 14 percent and not more than 25 percent of the total door area.

- add -- TABLE C402.1(2) and replace TABLE C402.1(4)

TABLE C402.1(4)

BUILDING ENVELOPE REQUIREMENTS--METAL BUILDING ASSEMBLY DESCRIPTIONS

BUILDING ENVELOPE REQUIREMENTS-- METAL BUILDING ASSEMBLY DESCRIPTIONS	DESCRIPTION	REFERENCE
ROOFS
Since Layer	The rated R-value of insulation is for insulation installed perpendicular to and draped over purlins and then compressed when the metal roof panels are attached. A minimum R-3 thermal spacer block between the purlins and the metal roof panels is required unless compliance is shown by the overall assembly U- factor.	ANSI/ASHRAE/IESNA 90.1-2019
Double Layer	The first rated R-value of insulation is for insulation installed perpendicular to and draped over purlins. The second rated R- value of insulation is for unfaced insulation installed above the first layer and parallel to the purlins and then compressed when the metal roof panels are attached. A minimum R-3 thermal spacer block between the purlins and the metal roof panels is required unless compliance is shown by the overall assembly U-factor.	ANSI/ASHRAE/IESNA 90.1-2019
Continuous Insulation	For assemblies with continuous insulation the continuous insulation is installed above or below the purlins, uncompressed and uninterrupted by framing members.	ANSI/ASHRAE/IESNA 90.1-2019
Liner system	A continuous membrane installed below the purlins and uninterrupted by framing members. Uncompressed, unfaced insulation rests on top of the membrane between the purlins. For multilayer installations, the last rated R-value of insulation is for unfaced insulation draped over purlins and then compressed when the metal roof panels are attached. A minimum R-5 thermal spacer block between the purlins and the metal roof panels is required unless compliance is shown by the overall assembly U-factor.	ANSI/ASHRAE/IESNA 90.1-2019
Filled Cavity (Fc)	The first rated R-value of insulation represents faced or unfaced insulation installed between the purlins. The second rated R-value of insulation represents unfaced insulation installed above the first layer, perpendicular to the purlins and compressed when the metal roof panels are attached. A supporting structure retains the bottom of the first layer at the prescribed depth required for the full thickness of insulation. A minimum R-5 thermal spacer block between the purlins and the metal roof panels is required unless compliance is shown by the overall assembly U-factor.	ANSI/ASHRAE/IESNA 90.1-2019
WALLS
Single-Layer Compressed	The first rated R-value of insulation is for insulation compressed between metal building wall panels and the steel structure.	ANSI/ASHRAE/IESNA 90.1-2019
Continuous Insulation	For assemblies with continuous insulation, the continuous insulation is installed on the outside or inside of the girts, uncompressed and uninterrupted by the framing members.	ANSI/ASHRAE/IESNA 90.1-2019
Single-Layer in Cavity	The insulation is installed in the cavity between the girts, not compressed by the framing. A membrane or facing, installed separately or adhered to the insulation, is installed inside of the girts to form a continuous layer. A thermal spacer block or thermal break strip between the girts and metal wall panels is required when specified in Table A3.2.3.	ANSI/ASHRAE/IESNA 90.1-2019
Double-Layer	The first rated R-value of insulation is for insulation installed in the cavity between the girts, not compressed by the framing. The second rated R-value of insulation is for insulation compressed between metal wall panels and the steel structure. A membrane or facing, installed separately or adhered to the insulation, is installed inside of the girts to form a continuous layer. A thermal spacer block or thermal break strip between the girts and metal wall panels is required when specified in Table A3.2.3.	ANSI/ASHRAE/IESNA 90.1-2019

- delete -- TABLE C402.1(3) and replace TABLE C402.1(5)

TABLE C402.1(5)

ASSEMBLY U-FACTORS FOR METAL BUILDING ROOFS

INSULATION SYSTEM	RATED R- VALUE OF INSULATION	OVERALL U-FACTOR FOR ENTIRE BASE ROOF ASSEMBLY	OVERALL U-FACTOR FOR ASSEMBLY OF BASE ROOF PLUS CONTINUOUS INSULATION (UNINTERRUPTED BY FRAMING)
			Rated R-Value of Continuous Insulation
Standing Seam Roofs with Thermal Spacer a Blocks			R-15.8	R-19	R-22.1	R-25	R-32	R-38
Single b layer	None	1.280	0.036				00.031	0.026
	R-10 R-11 R-13 R-16	0.115 0.107 0.101 0.096		0.036 0.035 0.035 0.034	0.032 0.032 0.031 0.031	0.030 0.029 0.029 0.028	0.025 0.024 0.024 0.024	0.021 0.021 0.021 0.021
	R-19	0.082		0.032	0.029	0.027	0.023	0.020
Double b layer	R-10 + R-10	0.088	0.037	0.033	0.030	0.028	0.023	0.020
	R-10 + R-11	0.086	0.036	0.033	0.030	0.027	0.023	0.020
	R-11 + R-11	0.085	0.036	0.033	0.030	0.027	0.023	0.020
	R-10 + R-13	0.084	0.036	0.032	0.029	0.027	0.023	0.020
	R-11 + R-13	0.082	0.036	0.032	0.029	0.027	0.023	0.020
	R-13 + R-13	0.075	0.034	0.031	0.028	0.026	0.022	0.019
	R-10 + R-19	0.074	0.034	0.031	0.028	0.026	0.022	0.019
	R-11 + R-19	0.072	0.034	0.030	0.028	0.026	0.022	0.019
	R-13 + R-19	0.068	0.033	0.030	0.027	0.025	0.021	0.019
	R-16 + R-19 R-19 + R-19	0.065 0.060	0.032 0.031	0.029 0.028	0.027 0.026	0.025 0.024	0.021 0.021	0.019 0.018
Liner c system	R-19 + R-11	0.037
	R-25 + R-8	0.037
	R-25 + R-11	0.031
	R-30 + R11	0.029
	R-25 + R-11 + R-11 LS	0.026
Filled c cavity	R-10 + R-19 Fc	0.041	0.025	0.023	0.022	0.020	0.018	0.016
Thru-fastened Roofs without Thermal Spacer Blocks
	R-10	0.184			0.036	0.033	0.027	0.023
	R-11	0.182			0.036	0.033	0.027	0.023
	R-13	0.174			0.036	0.033	0.026	0.023
	R-16	0.157			0.035	0.032	0.026	0.023
	R-19	0.151			0.035	0.032	0.026	0.022
Note: (Multiple R-values are listed in order from inside to outside) Shaded areas comply with minimum requirements for semi-conditioned spaces but not conditioned spaces. a. A standing seam roof clip that provides a minimum 1.5 inch distance between the top of the purlins and the underside of the metal building roof panels is required. b. A minimum R-3 thermal spacer block is required. c. A minimum R-5 thermal spacer block is required.

- delete -- TABLE C402.1(4) and replace TABLE C402.1(6)

TABLE C402.1(6)

ASSEMBLY U-FACTORS FOR ATTIC ROOFS WITH WOOD JOISTS

RATED R-VALUE OF INSULATION ALONE	OVERALL U-FACTOR FOR ENTIREa ROOF ASSEMBLY
Wood-framed Attic, Standard Framing
R-38	U-0.027
R-49	U-0.021
R-60	U-0.017
R-71	U-0.015
R-82	U-0.013
R-93	U-0.011
R-104	U-0.010
R-115	U-0.009
R-126	U-0.008
Wood-framed Attic, Advanced Framing
R-38	U-0.026
R-49	U-0.020
R-60	U-0.016
R-71	U-0.014
R-82	U-0.012
R-93	U-0.011
R-104	U-0.010
R-115	U-0.009
R-126	U-0.008
Wood Joists, Single-Rafter Roofb
R-38 + R-15ci	U-0.020
a. Lightly shaded areas comply with conditioned R-2 spaces, but not other conditioned building occupancies. Darkly shaded areas comply with minimum requirements for semi-conditioned spaces but not conditioned spaces. b. The first R-value is the cavity insulation, while the second value is the continuous insulation uninterrupted by framing.

- renumber -- TABLE C402.1(5) to TABLE C402.1(7)

- renumber -- TABLE C402.1(6) to TABLE C402.1(8)

- delete -- TABLE C402.1(7) and replace TABLE C402.1(9)

TABLE C402.1(9)

ASSEMBLY U-FACTORS FOR WOOD-FRAMED WALLS

RATED R- VALUE OF CAVITY INSULATION (EFFECTIVE INSTALLED)	OVERALL U- FACTOR FOR ASSEMBLY	OVERALL U-FACTOR FOR ASSEMBLY OF BASE WALL PLUS CONTINUOUS INSULATION (UNINTERRUPTED BY FRAMING)
		R-6	R-9	R-12	R-15	R-20	R-25	R-30	R-35	R-40
Wood Studs at 16 in. on Center and 3.5 in. Depth
R-0 (0.0)	0.292					0.042	0.035	0.030	0.026	0.023
R-11 (11.0)	0.096		0.050	0.044	0.038	0.032	0.028	0.024	0.022	0.020
R-13 (13.0)	0.089		0.047	0.041	0.037	0.031	0.027	0.024	0.021	0.019
R-15 (15.0)	0.083		0.045	0.039	0.035	0.030	0.026	0.023	0.020	0.019
Wood Studs at 16 in. on Center and 5.5 in. Depth
R-19 (18.0)	0.067	0.046	0.040	0.036	0.032	0.027	0.024	0.021	0.019	0.018
R-21 (21.0)	0.063	0.043	0.038	0.034	0.030	0.026	0.023	0.021	0.019	0.017
Wood Studs at 16 in. on Center and R-10 Headers
R-19 (18.0)	0.063	0.045	0.039	0.035	0.031	0.027	0.024	0.021	0.019	0.017
R-21 (21.0)	0.059	0.042	0.037	0.033	0.030	0.026	0.023	0.020	0.018	0.017
Wood Studs at 24 in. on Center and 3.5 in. Depth
R-0 (0.0)	0.298					0.042	0.035	0.030	0.026	0.023
R-11 (11.0)	0.094		0.050	0.043	0.038	0.032	0.027	0.024	0.022	0.019
R-13 (13.0)	0.086		0.047	0.041	0.036	0.031	0.026	0.023	0.021	0.019
R-15 (15.0)	0.080		0.044	0.039	0.035	0.029	0.026	0.023	0.020	0.018
Wood Studs at 24 in. on Center and 5.5 in. Depth
R-19 (18.0)	0.065	0.045	0.039	0.035	0.032	0.027	0.024	0.021	0.019	0.018
R-21 (21.0)	0.060	0.042	0.037	0.033	0.030	0.026	0.023	0.020	0.018	0.017
Wood Studs at 24 in. on Center and R-10 Headers
R-19 (18.0)	0.062	0.044	0.039	0.034	0.031	0.027	0.024	0.021	0.019	0.017
R-21 (21.0)	0.057	0.041	0.036	0.032	0.029	0.025	0.023	0.020	0.018	0.017

Note: Lightly shaded areas comply with building occupancies other than conditioned R-2 spaces. Darkly shaded areas comply with minimum requirements for semi-conditioned spaces but not conditioned spaces.

- delete and replace -- C402.1.1 Insulation component R-value-based method.

Building thermal envelope opaque assemblies shall comply with the requirements of Sections C402.2 and C402.3. For opaque portions of the building thermal envelope intended to comply on an insulation component R-value basis, the R-values for cavity insulation and continuous insulation shall be not less than that specified in the "Minimum R-values" columns of Table C402.1(2) and Table C402.1(3). Where cavity insulation is installed in multiple layers, the cavity insulation R-values shall be summed to determine compliance with the cavity insulation R- value requirements. Where continuous insulation is installed in multiple layers, the continuous insulation R-values shall be summed to determine compliance with the continuous insulation R-value requirements. Cavity insulation R-values shall not be used to determine compliance with the continuous insulation R-value requirements in Table C402.1(2) and Table C402.1(3). Commercial buildings or portions of commercial buildings enclosing conditioned spaces shall use the R-values from the "Conditioned Space" Table C402.1(2). Commercial buildings or portions of commercial buildings enclosing semi-conditioned spaces shall use the R-values from the "Semi-conditioned Space" Table C402.1(3). Walls between conditioned and semi- conditioned spaces shall use the R-values from the "Semi-conditioned Space" Table C402.1(3).

- delete and replace -- C402.1.2 Assembly U-factor, C-factor or F-factor-based method.

Building thermal envelope opaque assemblies shall meet the requirements of Sections C402.2 and C402.3. Building thermal envelope opaque assemblies intended to comply on an assembly U-, C- or F-factor basis shall have a U-, C- or F-factor not greater than that specified in the "Maximum Overall U-factor" columns of Table C402.1(2) and Table C402.1(3). Commercial buildings or portions of commercial buildings enclosing conditioned spaces shall use the U-, C- or F-factor from the "Conditioned Space" Table C402.1(2). Commercial buildings or portions of commercial buildings enclosing semi-conditioned spaces shall use the U-, C- or F-factor from the "Semi-conditioned Space" Table C402.1(3). Walls between conditioned and semi-conditioned spaces shall use the R-values from the "Semi-conditioned Space" Table C402.1(3).

- add -- C402.1.2.1 Roof/ceiling assembly.

The maximum, roof/ceiling assembly U-factor shall not exceed that specified in Table C402.1(2) and Table C402.1(3) based on construction materials used in the roof/ceiling assembly.

- add -- C402.1.2.1.1 Tapered, above-deck insulation based on thickness.

Where used as a component of a maximum roof/ceiling assembly U-factor calculation, the sloped roof insulation R-value contribution to that calculation shall use the average thickness in inches (mm) along with the material R-value-per-inch (per-mm) solely for U-factor compliance as prescribed in Section C402.1.1.

- add -- C402.1.2.1.2 Suspended ceilings.

Insulation installed on suspended ceilings having removable ceiling tiles shall not be considered part of the assembly U-factor of the roof/ceiling construction.

-add -- C402.1.2.1.3 Joints staggered.

Continuous insulation board shall be installed in not less than two layers, and the edge joints between each layer of insulation shall be staggered, except where insulation tapers to the roof deck at a gutter edge, roof drain or scupper.

-delete and replace -- C402.1.3 Component performance alternative.

Building envelope values and fenestration areas determined in accordance with Equation 4-1 shall be an alternative to compliance with the U-, F- and C-factors in Tables C402.1(2) and Table C402.1(3) and C402.3 and the maximum allowable fenestration areas in Section C402.3.1. Fenestration shall meet the applicable SHGC requirements of Section C402.3.3.

A + B + C + D + E [less than or equal] Zero (Equation 4-1)

where:

A	=	Sum of the (UA Dif) values for each distinct assembly type
UA Dif	=	of the building thermal envelope, other than slabs on grade and below-grade walls.
UA Proposed	=	UA Proposed - UA Table.
UA Table	=	Proposed U-value *Area.
B	=	(U-factor from Table C402.1(2) and Table C402.1(3) or C402.3) *Area.
FL Dif	=	Sum of the (FL Dif) values for each distinct slab on-grade perimeter condition of the building thermal envelope.
FL Proposed	=	FL Proposed - FL Table.
FL Table	=	Proposed F-value *Perimeter length.
C	=	$(F-factor specified in Table C402.1(2) and Table C402.1(3)$)
CA Dif	=	*Perimeter length.
CA Proposed	=	Sum of the (CA Dif) values for each distinct below-grade wall assembly type of the building thermal envelope.
CA Table	=	$(Maximum allowable C-factor specified in Table C402.1(2) and Table C402.1(3)$) *Area.

Where the proposed vertical glazing area is less than or equal to the maximum vertical glazing area allowed by Section C402.3.1, the value of D (Excess Vertical Glazing Value) shall be zero. Otherwise:

D	=	(DA *UV) - (DA *U Wall), but not less than zero.
DA	=	(Proposed Vertical Glazing Area) - (Vertical Glazing Area allowed by Section C402.3.1).
UA Wall	=	Sum of the (UA Proposed) values for each opaque assembly of the exterior wall.
U Wall	=	Area-weighted average U-value of all above-grade wall assemblies.
UAV	=	Sum of the (UA Proposed) values for each vertical glazing assembly.
UV	=	UAV/total vertical glazing area.

Where the proposed skylight area is less than or equal to the skylight area allowed by Section C402.3.1, the value of E (Excess Skylight Value) shall be zero. Otherwise:

E	=	(EA *US) - (EA *U Roof), but not less than zero.
EA	=	(Proposed Skylight Area) - (Allowable Skylight Area as specified in Section C402.3.1).
U Roof	=	Area-weighted average U-value of all roof assemblies.
UAS	=	Sum of the (UA Proposed) values for each skylight assembly.
US	=	UAS/total skylight area.

-delete and replace -- C402.1.4 Building above-grade performance alternative.

Above-grade building envelope values determined in accordance with Equation 4-2 shall be an alternative to compliance with the U-factors in Tables C402.1(2) and Table C402.1(3) and C402.3 and the maximum allowable fenestration areas in Section C402.3.1. Below-grade walls, floors, and slabs shall meet the applicable requirements of Section C402.1.1 or C402.1.2. Fenestration shall meet the applicable SHGC requirements of Section C402.3.3.

UA-Total/Area [less than or equal] 0.032 (Equation 4-2)

where:

UA-Total	=	Sum of the (UA) values for each distinct above- grade assembly type of the building thermal
UA	=	envelope including above-grade walls, roofs, doors, vertical fenestration, and skylights.
Area	=	Proposed U-value *Area.

-delete and replace -- C402.2 Specific building thermal envelope insulation requirements.

Insulation in building thermal envelope opaque assemblies shall comply with Sections C402.2.1 through C402.2.8 and Table C402.1(2) and Table C402.1(3).

-delete and replace -- C402.2.1 Roof assembly.

The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table C402.1(2) and Table C402.1(3), based on construction materials used in the roof assembly.

-add -- C402.2.1.1 Tapered, above-deck insulation based on thickness.

Where used as a component of a roof/ceiling assembly R-value calculation, the sloped roof insulation R- value contribution to that calculation shall use the average thickness in inches (mm) along with the material R-value-per-inch (per-mm) solely for R-value compliance as prescribed in Section 402.1.3.

-add -- C402.2.1.2 Minimum insulation, lowest point.

The minimum insulation of above deck roof insulation at its lowest point, gutter edge, roof drain or scupper, shall be not less than R-12.

-add -- C402.2.1.3 Suspended ceilings.

Insulation installed on suspended ceilings having removable ceiling tiles shall not be considered part of the minimum thermal resistance (R- value) of roof insulation in roof/ceiling construction.

-add -- C402.2.1.4 Joints staggered.

Continuous insulation board shall be installed in not less than two layers and the edge joints between each layer of insulation shall be staggered, except where insulation tapers to the roof deck at a gutter edge, roof drain or scupper.

-add -- C402.2.1.5 Mechanical curbs.

The minimum insulation of abovedeck roof insulation at the location of a mechanical curb, shall be not less than R-12.

-add -- C402.2.1.6 Skylight curbs.

Skylight curbs shall be insulated to the level of roofs with insulation entirely above the deck or R-10, whichever is less.

Exception: Unit skylight curbs included as a component of a skylight listed and labeled in accordance with NFRC 100 shall not be required to be insulated.

-delete and replace -- C402.2.2 Above-grade walls.

The minimum thermal resistance (R-value) of materials installed in the wall cavity between framing members and continuously on the walls shall be as specified in Table C402.1(2) and Table C402.1(3), based on framing type and construction materials used in the wall assembly. The R-value of integral insulation installed in concrete masonry units shall not be used in determining compliance with Table C402.1(2) and Table C402.1(3) except as otherwise noted in the table. In determining compliance with Table C402.1(2) and Table C402.1(3), the use of the U-factor of concrete masonry units with integral insulation shall be permitted. "Mass walls" where used as a component in the thermal envelope of a building shall comply with one of the following:

1. Weigh not less than 35 pounds per square foot (171 kg/m²) of wall surface area.

2. Weigh not less than 25 pounds per square foot (122 kg/m²) of wall surface area

where the material weight is not more than 120 pcf (1900 kg/m³).

3. Have a heat capacity exceeding 7 Btu/ft² * °F (144 kJ/m² * K).

4. Have a heat capacity exceeding 5 Btu/ft² * °F (103 kJ/m² * K), where the material weight is not more than 120 pcf (1900 kg/m³).

-delete and replace -- C402.2.3 Floors.

The thermal properties (component R-values or assembly U-, C- or F-factors) of floor assemblies over outdoor air or unconditioned space shall be as specified in Table C402.1(2) and Table C402.1(3), based on construction materials used in the floor assembly. Floor framing cavity insulation or structural slab insulation shall be installed to maintain permanent contact with the underside of the subfloor decking or structural slabs.

"Mass floors" where used as a component of the thermal envelope of a building shall provide one of the following weights:

1. 35 pounds per square foot (171 kg/m²) of floor surface area.

2. 25 pounds per square foot (122 kg/m²) of floor surface area where the material weight is not more than 120 pounds per cubic foot. (1923 kg/m³)

Exceptions:

1. The floor framing cavity insulation or structural slab insulation shall be permitted to be in contact with the top side of sheathing or continuous insulation installed on the bottom side of floor assemblies where combined with insulation that meets or exceeds the minimum U-value in Table C402.1(2) and Table C402.1(3) for "Metal framed" or "Wood framed and other" values for "Walls, Above Grade" and extends from the bottom to the top of all perimeter floor framing or floor assembly members.

2. Insulation applied to the underside of concrete floor slabs shall be permitted an airspace of not more than 1 inch (25 mm) where it turns up and is in contact with the underside of the floor under walls associated with the building thermal envelope.

-delete and replace -- C402.2.4 Slabs-on-grade.

The minimum thermal resistance (R-value) of the insulation for unheated or heated slab-on- grade floors designed in accordance with the R-value method of Section C402.1.1 shall be as specified in Table C402.1(2) and Table C402.1(3).

-add -- C402.2.4.1 Insulation installation.

Where installed, the perimeter insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The perimeter insulation shall extend downward from the top of the slab for the minimum distance shown in the table or to the top of the footing, whichever is less, or downward to not less than the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table. Insulation extending away from the building shall be protected by pavement or by not less than of 10 inches (254 mm) of soil. Where installed, full slab insulation shall be continuous under the entire area of the slab-on-grade floor, except at structural column locations and service penetrations. Insulation required at the heated slab perimeter shall not be required to extend below the bottom of the heated slab and shall be continuous with the full slab insulation.

Exception: Where the slab-on-grade floor is greater than 24 inches (61 mm) below the finished exterior grade, perimeter insulation is not required.

delete and replace C402.2.5 Below-grade walls.

The C-factor for the below-grade exterior walls shall be in accordance with Table C402.1(2) and Table C402.1(3). The R-value of the insulating material installed continuously within or on the below-grade exterior walls of the building envelope shall be in accordance with Table C402.1(2) and Table C402.1(3). The C-factor or R-value required shall extend to a depth of not less than 10 feet (3048 mm) below the outside finished ground level, or to the level of the lowest floor of the conditioned space enclosed by the below-grade wall, whichever is less.

delete and replace C402.2.6 Insulation of radiant heating systems.

Radiant heating system panels, and their associated components that are installed in interior or exterior assemblies shall be insulated to an R-value of not less than R-3.5 on all surfaces not facing the space being heated. Radiant heating system panels that are installed in the building thermal envelope shall be separated from the exterior of the building or unconditioned or exempt spaces by not less than the R-value of insulation installed in the opaque assembly in which they are installed or the assembly shall comply with Section C402.1.2.

Exception: Heated slabs on grade insulated in accordance with the "Heated slabs" row of Table C402.1(2) and Table C402.1(3).

delete and replace C402.2.7 Airspaces.

Where the R-value of an airspace is used for compliance in accordance with Section C402.1, the airspace shall be enclosed in an unventilated cavity constructed to minimize airflow into and out of the enclosed airspace. Airflow shall be deemed minimized where the enclosed airspace is located on the interior side of the continuous air barrier and is bounded on all sides by building components.

Exception: The thermal resistance of airspaces located on the exterior side of the continuous air barrier and adjacent to and behind the exterior wall-covering material shall be determined in accordance with ASTM C1363 modified with an airflow entering the bottom and exiting the top of the airspace at an air movement rate of not less than 70 mm/second.

delete and replace C402.3 Fenestration.

Fenestration shall comply with Sections C402.3.1 through C402.3.5 and Table C402.3. Daylight responsive controls shall comply with this section and Section C405.2.3.1.

delete and replace TABLE C402.3

TABLE C402.3

BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR AND SHGC REQUIREMENTS

VERTICAL FENESTRATION
U-factor
Fixed fenestration other than storefront	0.29
Storefront fenestration	0.33
Operable fenestration, R-2 occupancy classifications	0.30
Operable fenestration, occupancy classifications other than R-2	0.36
Entrance doors	0.63
SHGC
PF	Fixed	Operable
PF < 0.2	0.38	0.34
0.2 $(less than or equal$) PF < 0.5	0.46	0.41
PF $(greater than or equal$) 0.5	0.61	0.54
SKYLIGHTS
U-factor	0.41
SHGC	0.38

NR = No requirement, PF = Projection factor.

delete and replace C402.3.1.1 Increased vertical fenestration area with daylight responsive controls (see Section C405.2.3).

Not more than 40 percent of the gross above-grade wall area shall be vertical fenestration, provided that all of the following requirements are met:

1. In buildings not greater than two stories above grade, not less than 50 percent of the net floor area is within a daylight zone.

2. In buildings three or more stories above grade, not less than 25 percent of the net floor area is within a daylight zone.

3. Daylight responsive controls are installed in daylight zones.

4. Visible transmittance (VT) of vertical fenestration is not less than 1.1 times solar heat gain coefficient (SHGC).

Exception: Fenestration that is outside the scope of NFRC 200 is not required to comply with Item 4.

delete and replace C402.3.1.2 Increased skylight area with daylight responsive controls.

The skylight area shall be not more than 6 percent of the roof area provided that daylight responsive controls are installed in toplit daylight zones.

delete and replace C402.3.2 Minimum skylight fenestration area.

Skylights shall be provided in enclosed spaces greater than 2,500 square feet (232 m) in floor area, directly under a roof with not less than 75 percent of the ceiling area with a ceiling height greater than 15 feet (4572 mm), and used as an office, lobby, atrium, concourse, corridor, storage space, gymnasium/exercise center, convention center, automotive service area, space where manufacturing occurs, nonrefrigerated warehouse, retail store, distribution/sorting area, transportation depot or workshop. The total toplit daylight zone shall be not less than half the floor area and shall comply with one of the following:

1. A minimum skylight area to toplit daylight zone of not less than 3 percent where all skylights have a VT of not less than 0.40, or VTannual of not less than 0.26, as determined in accordance with Section C303.1.3.

2. A minimum skylight effective aperture of not less than 1 percent, determined in accordance with Equation 4-3, of:

2.1 Not less than 1 percent, using a skylight's VT rating; or

2.2 Not less than 0.66 percent using a Tubular Daylighting Device's VT annual rating.

Click here to view image

where:

Skylight area	=	Total fenestration area of skylights.
Skylight VT	=	Area weighted average visible transmittance of skylights.
WF	=	Area weighted average well factor, where well factor is 0.9 if light well depth is less than 2 feet (610 mm), or 0.7 if light well depth is 2 feet (610 mm) or
Light well depth	=	greater, or 1.0 for Tubular Daylighting Devices with VTannual ratings.

Exception: Skylights above daylight zones of enclosed spaces are not required in:

1. Spaces where the designed general lighting power densities are less than 0.5 W/ft (5.4 W/m2).

2. Areas where it is documented that existing structures or natural objects block direct beam sunlight on not less than half of the roof over the enclosed area for more than 1,500 daytime hours per year between 8 a.m. and 4 p.m.

3. Spaces where the daylight zone under rooftop monitors is greater than 50 percent of the enclosed space floor area.

-- Spaces where the total area minus the area of sidelit daylight zones is less than 2,500 square feet (232 m2), and where the lighting is controlled in accordance with Section C405.2.3.

-- Spaces designed as storm shelters complying with ICC 500.

delete and replace C402.3.2.1 Lighting controls in toplit daylight zones.

Daylight responsive controls shall be provided in toplit daylight zones.

delete and replace C402.3.2.2 Haze factor.

Skylights in office, storage, automotive service, manufacturing, nonrefrigerated warehouse, retail store and distribution/sorting area spaces shall have a glazing material or diffuser with a haze factor greater than 90 percent when tested in accordance with ASTM D1003.

Exception: Skylights and tubular daylighting devices designed and installed to exclude direct sunlight entering the occupied space by the use of fixed or automated baffles or the geometry of skylight and light well or the use of optical diffuser components.

delete and replace C402.3.5 Doors.

Opaque swinging doors shall comply with Table C402.1(2) and Table C402.1(3). Opaque nonswinging doors shall comply with Table C402.1(2) and Table C402.1(3). Opaque doors shall be considered as part of the gross area of above-grade walls that are part of the building thermal envelope. Opaque doors shall comply with Section C402.3.5.1 or C402.3.5.2. Other doors shall comply with the provisions of Section C402.3.3 for vertical fenestration.

add C402.3.5.1 Opaque swinging doors.

Opaque swinging doors shall comply with Table C402.1(2) and Table C402.1(3).

add C402.3.5.2 Nonswinging doors.

Opaque nonswinging doors that are horizontally hinged sectional doors with a single row of fenestration shall have an assembly U-factor less than or equal to 0.360, provided that the fenestration area is not less than 14 percent and not more than 25 percent of the total door area.

Exception: Other doors shall comply with the provisions of Section C402.4.3 for vertical fenestration.

delete and replace C402.4 Air leakage--thermal envelope.

The building thermal envelope shall comply with Sections C402.4.1 through C402.4.6.

delete and replace C402.4.1 Air barriers.

A continuous air barrier shall be provided throughout the building thermal envelope. The continuous air barriers shall be located on the inside or outside of the building thermal envelope, located within the assemblies composing the building thermal envelope, or any combination thereof. The air barrier shall comply with Section C402.4.1.1.

Exceptions:

1. For buildings larger than 250,000 ft² (25,000 m²), that do not include Group R or Group I occupancies, the air barrier shall either comply with section C402.4.1.1 or Sections C402.4.1.2 through C402.4.1.8.

2. Where air barrier performance testing is determined unfeasible by the Vermont Department of Public Service, the air barrier shall comply with sections C402.4.1.2 through C402.4.1.8.

delete and replace C402.4.1.1 Air barrier performance testing.

The building thermal envelope shall be tested in accordance with ASTM E779, ANSI/RESNET/ICC 380, ASTME3158 OR ASTM E1827 or an equivalent method approved by the Vermont Department of Public Service. The measured air leakage shall not exceed 0.25 cfm/ft2 of the building thermal envelope area at a pressure differential of 0.3 inch water gauge (75 Pa). Alternatively, portions of the building shall be tested and the measured air leakages shall be area weighted by the surface areas of the building envelope in each portion. The weighted average test results shall not exceed the whole building leakage limit. In the alternative approach, the following portions of the building shall be tested:

1. The entire envelope area of all stories that have any spaces directly under a roof.

2. The entire envelope area of all stories that have a building entrance, exposed floor, or loading dock, or are below grade.

3. Representative above-grade sections of the building totaling at least 25 percent of the wall area enclosing the remaining conditioned space.

Exception: R-2 building occupancies six stories or less shall be tested at a pressure differential of 0.2 inch water gauge (50 Pa), and the measured air leakage shall not exceed 0.15 cfm/ft2 of the building thermal envelope area.

delete and replace C402.4.1.4.1 Materials.

Materials with an air permeability not greater than 0.004 cfm/ft2 (0.02 L/s -- m2) under a pressure differential of 0.3 inch water gauge (75 Pa) when tested in accordance with ASTM E2178 shall comply with this section. Materials in Items 1 through 16 shall be deemed to comply with this section, provided that joints are sealed and materials are installed as air barriers in accordance with the manufacturer's instructions.

1. Plywood with a thickness of not less than 3/8 inch (10 mm).

2. Oriented strand board having a thickness of not less than3/8 inch (10 mm).

3. Extruded polystyrene insulation board having a thickness of not less than 1/2 inch (12.7 mm).

4. Foil-back polyisocyanurate insulation board having a thickness of not less 1/2 than / inch (12.7 mm).

5. Closed-cell spray foam having a minimum density of 1.5 pcf (2.4 kg/m3) and having a thickness of not less than 1/2inches (38 mm).

6. Open-cell spray foam with a density between 0.4 and 1.5 pcf (0.6 and 2.4 kg/m3) and having a thickness of not less than 4.5 inches (113 mm).

7. Exterior or interior gypsum board having a thickness of not less than 1/2 inch (12.7 mm).

8. Cement board having a thickness of not less than 1/2/ inch (12.7 mm).

9. Built-up roofing membrane.

10. Modified bituminous roof membrane.

11. Single-ply roof membrane.

12. A Portland cement/sand parge, or gypsum plaster having a thickness of not 5/8 less than / inch (15.9 mm).

13. Cast-in-place and precast concrete.

14. Fully grouted concrete block masonry.

15. Sheet steel or aluminum.

16. Solid or hollow masonry constructed of clay or shale masonry units.

delete and replace C402.4.1.4.2 Assemblies.

Assemblies of materials and components with an average air leakage not greater than 0.04 cfm/ft (0.2 L/s -- m) under a pressure differential of 0.3 inch of water

gauge (w.g.)(75 Pa) when tested in accordance with ASTM E2357, ASTM E1677, ASTM D8052 or ASTM E283 shall comply with this section. Assemblies listed in Items 1 through 3 shall be deemed to comply, provided that joints are sealed and the requirements of Section C402.4.1.3 are met.

1. Concrete masonry walls coated with either one application of block filler or two applications of a paint or sealer coating.

2. Masonry walls constructed of clay or shale masonry units with a nominal width of 4 inches (102 mm) or more.

3. A Portland cement/sand parge, stucco or plaster not less than 1/2 inch (12.7 mm) in thickness.

delete and replace C402.4.1.6 Rooms containing fuel-burning appliances that are not direct vented.

Where combustion air is supplied through openings in an exterior wall to a room or space containing a space-conditioning fuel-burning appliance, one of the following shall apply:

1. The room or space containing the appliance shall be located outside of the building thermal envelope.

2. The room or space containing the appliance shall be enclosed and isolated from conditioned spaces inside the building thermal envelope. Such rooms shall comply with all of the following:

2.1. The walls, floors and ceilings that separate the enclosed room or space from conditioned spaces shall be insulated to be not less than equivalent to the insulation requirement of below-grade walls as specified in Table C402.1(2) and Table C402.1(3).

2.2. The walls, floors and ceilings that separate the enclosed room or space from conditioned spaces shall be sealed in accordance with Section C402.4.1.3.

2.3. The doors into the enclosed room or space shall be fully gasketed.

2.4. Water lines and ducts in the enclosed room or space shall be insulated in accordance with Section C403.

2.5. Where an air duct supplying combustion air to the enclosed room or space passes through conditioned space, the duct shall be insulated to an R-value of not less than R-10.

Exception: Fireplaces and stoves complying with Section 2111.14 of the International Building Code.

delete and replace C402.4.2 Dwelling and sleeping unit enclosure testing.

The building thermal envelope shall be tested in accordance with ASTM E779, ANSI/RESNET/ICC 380, ASTM E1827 or an equivalent method approved by the code official. The measured air leakage shall not exceed 0.15 cfm/ft2 (1.5 L/s m2) of the testing unit enclosure area at a pressure differential of 0.2 inch water gauge (50 Pa). Where multiple dwelling units or sleeping units or other occupiable conditioned spaces are contained within one building thermal envelope, each unit shall be considered an individual testing unit, and the building air leakage shall be the weighted average of all testing unit results, weighted by each testing unit's enclosure area. Units shall be tested separately with an unguarded blower door test as follows:

1. Where buildings have fewer than eight testing units, each testing unit shall be tested.

2. For buildings with eight or more testing units, the greater of seven units or 20 percent of the testing units in the building shall be tested, including a top floor unit, a ground floor unit and a unit with the largest testing unit enclosure area. For each tested unit that exceeds the maximum air leakage rate, an additional two units shall be tested, including a mixture of testing unit types and locations.

delete and replace C402.4.4 Loading dock weather seals.

Cargo door openings and loading door openings shall be equipped with weather seals that restrict infiltration and provide direct contact along the top and sides of vehicles that are parked in the doorway. If equipped with an interior dock leveler, the deck of the leveler, rear pit wall, and the deck plate shall be insulated with a minimum of 1.5 inches of sprayed closed cell foam. The side pit walls and pit slab shall be insulated in accordance with the ASTM E283 slab on grade standard found in Table C402.1(2) and Table C402.1(3). The spaces between the pit wall and the deck skirts for the leveler shall be weather-stripped. Provide each dock board with an exterior face closure curtain to reduce air infiltration under the dock board.

add C402.4.6 Operable openings interlocking.

Where occupancies utilize operable openings to the outdoors that are larger than 40 square feet (3.7 m2) in area, such openings shall be interlocked with the heating and cooling system so as to raise the cooling setpoint to 90°F (32°C) and lower the heating setpoint to 55°F (13°C) whenever the operable opening is open. The change in heating and cooling setpoints shall occur within 10 minutes of opening the operable opening.

Exceptions:

1. Separately zoned areas associated with the preparation of food that contain appliances that contribute to the HVAC loads of a restaurant or similar type of occupancy.

2. Warehouses that utilize overhead doors for the function of the occupancy.

3. The first entrance doors where located in the exterior wall and are part of a vestibule system.

add C402.4.6.1 Operable controls.

Controls shall comply with Section C403.14.

add C402.5 Solar-ready zone

add C402.5.1 General.

A solar-ready zone shall be located on the roof of buildings and are oriented between 110 degrees and 270 degrees of true north or have low-slope roofs. Solar-ready zones shall comply with Sections C402.5.2 through C402.5.8.

Exceptions:

1. A building with a permanently installed, on-site renewable energy system.

2. A building with a solar-ready zone that is shaded for more than 70 percent of daylight hours annually.

3. A building where the licensed design professional certifies that the incident solar radiation available to the building is not suitable for a solar-ready zone.

4. A building where the licensed design professional certifies that the solar zone area required by Section C402.5.3 cannot be met because of extensive rooftop equipment, skylights, vegetative roof areas or other obstructions.

add C402.5.2 Construction document requirements for a solar-ready zone.

Construction documents shall indicate the solar-ready zone.

add C402.5.3 Solar-ready zone area.

The total solar-ready zone area shall be not less than 40 percent of the roof area calculated as the horizontally projected gross roof area less the area covered by skylights, occupied roof decks, vegetative roof areas and mandatory access or set back areas as required by the International Fire Code. The solar-ready zone shall be a single area or smaller, separated sub-zone areas. Each sub- zone shall be not less than 5 feet (1524 mm) in width in the narrowest dimension.

add C402.5.4 Obstructions.

Solar ready zones shall be free from obstructions, including pipes, vents, ducts, HVAC equipment, skylights and roof-mounted equipment.

add C402.5.5 Roof loads and documentation.

A collateral dead load of not less than 5 pounds per square foot (5 psf) (24.41 kg/m) shall be included in the gravity and lateral design calculations for the solar-ready zone. The structural design loads for roof dead load and roof live load shall be indicated on the construction documents.

add C402.5.6 Interconnection pathway.

Construction documents shall indicate pathways for routing of conduit or piping from the solar-ready zone to the electrical service panel and electrical energy storage system area or service hot water system.

add C402.5.7 Electrical energy storage system-ready area.

The floor area of the electrical energy storage system-ready area shall be not less than 2 feet (610 mm) in one dimension and 4 feet (1219 mm) in another dimension and located in accordance with rules adopted by Vermont fire safety code. The location and layout diagram of the electrical energy storage system-ready area shall be indicated on the construction documents.

add C402.5.8 Electrical service reserved space.

The main electrical service panel shall have a reserved space to allow installation of a dual-pole circuit breaker for future solar electric and a dual-pole circuit breaker for future electrical energy storage system installation. These spaces shall be labeled "For Future Solar Electric and Storage." The reserved spaces shall be positioned at the end of the panel that is opposite from the panel supply conductor connection.

Section C403. Building Mechanical Systems.

delete and replace C403.1 General.

In addition to the mechanical requirements of Section C403, projects must achieve the required number of credits based on building occupancy group as outlined in Table C406.1.1 and Table C406.1.2. To achieve the required credits, mechanical enhancements may be needed.

The requirements of C403 that may be affected and the corresponding C406 references are summarized in Table C403.1(1). For a full list of potential measures see Table C406.2.1 and Table C406.3.1.

add TABLE C403.1(1)

TABLE C403.1(1):

C406 MEASURES AFFECTING MECHANICAL SYSTEMS

ID	C406 Measure Title	C403 Reference	C406 Section
H01	HVAC Performance	n/a	C406.2.2.1
H02	Heating efficiency	C403.3.2	C406.2.2.2
H03	Cooling efficiency	C403.3.2	C406.2.2.3
H04	Residential HVAC control	C403.7.6	C406.2.2.4
H05	Energy Recovery	C403.7.3	C406.2.2.5
Q04	Fault Detection	C403.2.3	C406.2.4
G02	HVAC Load Management	n/a	C406.3.3
G05	Cooling Energy Storage	n/a	C406.3.6
G07	Building Thermal Mass	n/a	C406.3.8

Mechanical systems and equipment serving the building heating, cooling, ventilating or refrigerating needs shall comply with one of the following:

1. Sections C403.1.1 and C403.2 through C403.14

2. Data Centers shall comply with C403.1.1, C403.1.2 and C403.6 through C403.14

3. Section C403.1.3 and Sections within Section C403 that are listed in Table C407.2

Exception: Data center systems are exempt from the requirements of Sections C403.4 and C403.5.

add C403.1.2 Data centers.

Data center systems shall comply with Sections 6 and 8 of ASHRAE 90.4 with the following changes:

1. Replace maximum design mechanical load component (MLC) values specified in Table 6.2.1.1 of the ASHRAE 90.4 with the value in Table C403.1.2(1).

2. Replace maximum annualized MLC values specified in Table 6.2.1.2 of the ASHRAE 90.4 with the value in Table C403.1.2(2).

add TABLE C403.1.2(1)

TABLE C403.1.2(1)

MAXIMUM DESIGN MECHANICAL LOAD COMPONENT (DESIGN MLC)

CLIMATE ZONE	DESIGN MLC AT 100% AND AT 50% ITE LOAD
6A	0.22

add TABLE C403.1.2(2)

TABLE C403.1.2(2)

MAXIMUM ANNUALIZED MECHANICAL LOAD COMPONENT (ANNUALIZED MLC)

CLIMATE ZONE	HVAC MAXIMUM ANNUALIZED MLC AT 100% AND AT 50% ITE LOAD
6A	0.17

add C403.1.3 HVAC total system performance ratio (HVAC TSPR).

HVAC systems serving buildings or portions of buildings listed in C403.1.3.1 that are not served by systems listed in C403.1.3.2 shall have an HVAC total system performance ratio (HVAC TSPR) of the proposed design HVAC systems that is greater than or equal to the HVACTSPR of the standard reference design divided by the applicable mechanical performance factor (MPF) from Table C409.3.1. HVAC TSPR shall be calculated in accordance with Section C409, Calculation of HVAC Total System Performance Ratio.

Systems using the HVAC TSPR method shall also meet requirements in C403.1.3.3. C403.1.3.1 Included Building Types. HVAC systems that serve the following building use types are allowed to use the TSPR Method:

1. occupancy group B,

2. occupancy group M,

3. occupancy group A-3,

4. occupancy group E,

5. occupancy group R-1,

6. the dwelling units and common areas within occupancy group R-2 multifamily buildings.

add C403.1.3.2 Excluded Systems.

The following HVAC systems are excluded from using the TSPR Method:

1. HVAC Systems using

1.1 district heating water, chilled water or steam

2.1 small duct high velocity air cooled, space constrained air cooled, single package vertical air conditioner, single package vertical heat pump, or

3.1 double-duct air conditioner or double-duct heat pump as defined in subpart F to 10CFR part 431

4.1 packaged terminal air conditioners and packaged terminal heat pumps that have cooling capacity greater than 12,000 Btu/hr 5.(3500 kW)

5.1 a common heating source serving both HVAC and service water heating equipment, or

2. HVAC systems that provide recovered heat for service water heating

3. HVAC systems not included in Table C409.5.2.10.1

4. HVAC systems included in table C409.5.2.10.1 with parameters in Table C409.5.2.10.2, not identified as applicable to that HVAC system type.

5. HVAC systems with chilled water supplied by absorption chillers, heat recovery chillers, water to water heat pumps, air to water heat pumps, or a combination of air and water cooled chillers on the same chilled water loop.

6. HVAC systems served by heating water plants that include air to water or water to water heat pumps.

7. Underfloor air distribution and displacement ventilation HVAC systems.

8. Space conditioning systems that do not include mechanical cooling.

9. HVAC systems serving laundry rooms, elevator rooms, mechanical rooms, electrical rooms, data centers, and computer rooms.

10. Buildings or areas of medical office buildings that comply fully with ASHRAE Standard 170, including but not limited to surgical centers, or that are required by other applicable codes or standards to provide 24/7 air handling unit operation

11. HVAC systems serving laboratories with fume hoods

12. Locker rooms with more than 2 showers

13. Natatoriums and rooms with saunas

14. Restaurants and commercial kitchens with total cooking capacity greater than 100,000 Btu/h

15. Areas of buildings with commercial refrigeration equipment exceeding 100 kW of power input.

16. Cafeterias and dining rooms

add C403.1.3.3 TSPR Method Partial Prescriptive Requirements.

HVAC systems using the HVAC Performance Rating Method shall meet relevant prescriptive requirements in Section C403 as follows:

1. Air economizers shall meet the requirements of Section C403.5.3.4 "relief of excess outdoor air" and Section C403.5.5 "Economizer fault detection and diagnostics."

2. Variable-air-volume system systems shall meet requirements of Sections C403.6.5, C403.6.6, and C403.6.9.

3. Hydronic systems shall meet the requirements of C403.4.4.

4. Plants with multiple chillers or boilers shall meet the requirements of Section C403.4.5.

5. Hydronic (Water Loop) Heat Pumps and Water-Cooled Unitary Air Conditioners shall meet the requirements of Section C403.4.3.3.

6. Cooling tower turndown shall meet requirements of Section C403.10.4.

7. Heating of unenclosed spaces shall meet the requirements of Section C403.13.1.

8. Hot-gas bypass shall meet the requirements of Section C403.3.3.

9. Systems shall meet the operable openings interlock requirements of Section C402.5.11.10.

10. Refrigeration systems shall meet the requirements of Section C403.11.

delete and replace C403.2 System design

Mechanical systems shall be designed to comply with Sections C403.2.1 through C403.2.3 Where elements of a building's mechanical systems are addressed in Sections C403.3 through C403.14, such elements shall comply with the applicable provisions of those sections. Hydronic heating systems and associated equipment shall be sized for and operated at a maximum heating hot water temperature of 140F. Construction documents shall include submittal of a Sequence of Operations for all mechanical equipment, including a specification outlining each of the functions required by this section.

delete and replace C403.2.2 Ventilation

Ventilation, either natural or mechanical, shall be provided in accordance with. ASHRAE Standard 62.1. Where mechanical ventilation is provided, the system shall provide the capability to reduce the outdoor air supply to the minimum required by ASHRAE Standard 62.1. The design professional shall utilize ventilation rates based on the expected occupancy level of the space. Life safety maximum allowable occupancy density shall not be used as a ventilation basis of design.

Exception: All Residential occupancies. See the ventilation requirements of Section 304 of the Vermont Residential Building Energy Standards.

delete and replace C403.2.4 Fault detection and diagnostics.

New buildings with an HVAC system serving a gross conditioned floor area of 100,000 square feet (9290 m2) or larger shall include a fault detection and diagnostics (FDD) system to monitor the HVAC system's performance and automatically identify faults. The FDD system shall:

1. Include permanently installed sensors and devices to monitor the HVAC system's performance.

2. Sample the HVAC system's performance at least once every 15 minutes.

3. Automatically identify and report HVAC system faults.

4. Automatically notify authorized personnel of identified HVAC system faults.

5. Automatically provide prioritized recommendations for repair of identified faults based on analysis of data collected from the sampling of HVAC system performance.

6. Be capable of transmitting the prioritized fault repair recommendations to remotely located authorized personnel.

Exception: R-1 and R-2 occupancies.

add C403.2.5 Mechanical systems commissioning and completion requirements. Mechanical systems shall be commissioned and completed in accordance with Section C407

delete and replace C403.3 Heating and cooling equipment efficiencies

Heating and cooling equipment installed in mechanical systems shall be sized in accordance with Section C403.3.1 and shall be not less efficient in the use of energy than as specified in Section C403.3.2.

delete and replace C403.3.1 Equipment sizing

The output capacity of heating and cooling equipment shall be not greater than that of the smallest available equipment size that exceeds the loads calculated in accordance with Section C403.1.1. A single piece of equipment providing both heating and cooling shall satisfy this provision for one function with the capacity for the other function as small as possible, within available equipment options. Heating and cooling equipment sizing is permitted to be up to 10 percent greater (to the next nearest available size) than the calculated peak heating and cooling loads to allow for building pickup and cool down after temperature setback conditions or for proper airflow volumes. Heat pump equipment shall not be sized greater than the calculated peak heating and cooling loads, as they are exempt from temperature setbacks and are significantly less efficient when oversized. Outdoor condensing units serving multiple indoor heat pump units shall be sized equal or less than the total capacity of the indoor units.

Exceptions:

1. Required standby equipment and systems provided with controls and devices that allow such systems or equipment to operate automatically only when the primary equipment is not operating.

2. Multiple units of the same equipment type with combined capacities exceeding the design load and provided with controls that are configured to sequence the operation of each unit based on load.

delete and replace TABLE C403.3.2(1)

TABLE C403.3.2(1)

ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS - MINIMUM EFFICIENCY REQUIREMENTS [c, ] [d ]

EQUIPMENT TYPE	SIZE CATEGORY	HEATING SECTION TYPE	SUBCATEGORY OR RATING CONDITION	MINIMUM EFFICIENCY	PROCEDURE
Air conditioners, air cooled	< 65,000 b Btu/h	All	Split system, three phase	13.0 SEER	AHRI 210/240-2017 before 1/1/23 AHRI 210/240 - 2023 after 1/1/2023
				before
				1/1/2023 13.4 SEER2
				after 1/1/2023
			Single package, three phase	14.0 SEER
				before 1/1/2023 13.4 SEER2
				after 1/1/23
Space constrained, aircooled	$(less than or equal$)30,000 Btu/hb	All	Split System, three phase	12.0 SEER before 1/1/2023 11.7 SEER2	AHRI 210/240 - 2017 before 1/1/2023
				after 1/1/2023	AHRI 210/240 - 2023 after 1/1/2023
			Single package, three phase	12.0 SEER before 1/1/2023 11.7 SEER2 after 1/1/2023
Small duct, high- velocity, air cooled	< 65,000 b Btu/h	All	Split System, three phase	12.0 SEER before 1/1/2023 12.1 SEER2 after 1/1/2023	AHRI 210/240 - 2017 before 1/1/2023 AHRI 210/240 - 2023 after 1/1/2023
Air conditioners, air cooled	$(greater than or equal$) 65,000 Btu/h and < 135,000 Btu/h	Electric resistance (or none)	Split system and single package	11.2 EER 12.9 IEER before 1/1/2023 14.8 IEER after 1/1/2023	AHRI 340/360
		All other		11.0 EER 12.7 IEER before 1/1/2023 14.6 IEER after 1/1/2023
	$(greater than or equal$) 135,000 Btu/h and < 240,000 Btu/h	Electric resistance (or none)		11.0 EER 12.4 IEER before 1/1/2023 14.2 IEER after 1/1/2023
		All other		10.8 EER 12.2 IEER before 1/1/2023 14.0 IEER after 1/1/2023
	$(greater than or equal$) 240,000 Btu/h and < 760,000 Btu/h	Electric resistance (or none)		10.0 EER 11.6 IEER before 1/1/2023 13.2 IEER after 1/1/2023
		All other		9.8 EER 11.4 IEER before 1/1/2023 13.0 IEER after 1/1/2023
	$(greater than or equal$) 760,000 Btu/h	Electric resistance (or none)		9.7 EER 11.2 IEER before 1/1/2023 12.5 IEER after 1/1/2023
		All other		9.5 EER 11.0 IEER before 1/1/2023 12.3 IEER after 1/1/2023
Air conditioners, water cooled	< 65,000 Btu/h	All	Split system and single package	12.1 EER 12.3 IEER	AHRI 210/240
	$(greater than or equal$) 65,000 Btu/h and < 135,000 Btu/h	Electric resistance (or none)		12.1 EER 13.9 IEER	AHRI 340/360
		All other		11.9 EER 13.7 IEER
	$(greater than or equal$) 135,000 Btu/h and < 240,000 Btu/h	Electric resistance (or none)		12.5 EER 13.9 IEER
		All other		12.3 EER 13.7 IEER
	$(greater than or equal$) 240,000 Btu/h and < 760,000 Btu/h	Electric resistance (or none)		12.4 EER 13.6 IEER
		All other		12.2 EER 13.4 IEER
	$(greater than or equal$) 760,000 Btu/h	Electric resistance (or none)		12.2 EER 13.5 IEER
		All other		12.0 EER 13.3 IEER

TABLE C403.3.2(1)--continued MINIMUM EFFICIENCY REQUIREMENTS:

ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS

EQUIPMENT TYPE
	SIZE CATEGORY	HEATING SECTION TYPE	SUB- CATEGORY OR RATING CONDITION	MINIMUM EFFICIENCY	TEST a PROCEDURE
Air conditioners, evaporatively cooled	< 65,000 b Btu/h	All	Split system and single package	12.1 EER 12.3 IEER	AHRI 210/240
	$(greater than or equal$) 65,000 Btu/h and < 135,000 Btu/h	Electric resistance (or none)		12.1 EER 12.3 IEER	AHRI 340/360
		All other		11.9 EER 12.1 IEER
	$(greater than or equal$) 135,000 Btu/h and < 240,000 Btu/h	Electric resistance (or none)		12.0 EER 12.2 IEER
		All other		11.8 EER 12.0 IEER
	$(greater than or equal$) 240,000 Btu/h and < 760,000 Btu/h	Electric resistance (or none)		11.9 EER 12.1 IEER
		All other		11.7 EER 11.9 IEER
	$(greater than or equal$) 760,000 Btu/h	Electric resistance (or none)		11.7 EER 11.9 IEER
		All other		11.5 EER 11.7 IEER
Condensing units, air cooled	$(greater than or equal$) 135,000 Btu/h	--	--	10.5 EER 11.8 IEER	AHRI 365
Condensing units, water cooled	$(greater than or equal$) 135,000 Btu/h	--	--	13.5 EER 14.0 IEER	AHRI 365
Condensing units, evaporatively cooled	$(greater than or equal$) 135,000 Btu/h	--	--	13.5 EER 14.0 IEER	AHRI 365

For SI: 1 British thermal unit per hour = 0.2931 W.

a. Chapter 6 contains a complete specification of the referenced test procedure, including the reference year version of the test procedure.

b. Single-phase, US air-cooled air conditioners less than 65,000 Btu/h are regulated as consumer products by the US Department of Energy Code of Federal Regulations DOE 10 CFR 430 . SEER and SEER2 values for single- phase products are set by the US Department of Energy.

c. DOE 10 CFR 430 Subpart B Appendix M1 includes the test procedure updates effective 1/1/2023 that will be incorporated in AHRI 210/240--2023.

d. This table is a replica of ASHRAE 90.1 Table 6.8.1-1 Electrically Operated Unitary Air Conditioners and Condensing Units--Minimum Efficiency Requirements.

delete and replace TABLE C403.3.2(2

TABLE C403.3.2(2)

Notes

31-003 Code Vt. R. 31-000-003-X

EFFECTIVE DATE:
Original effective date not provided.
AMENDED:
January 3, 2012 Secretary of State Rule Log #11-041; March 1, 2015 Secretary of State Rule Log #14-045; September 1, 2020 Secretary of State Rule Log #19-073; 7/1/2024 Secretary of State Rule Log #23-019

STATUTORY AUTHORITY:

30 V.S.A. § 53