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Virginia Administrative Code
Title 13. Housing
Agency 5. Department of Housing And Community Development
Chapter 63. Virginia Uniform Statewide Building Code
5/28/2024

13VAC5-63-264. Chapter 13 Energy efficiency.

Add Section 1301.1.1.1 to the IBC to read:

1301.1.1.1 Changes to the IECC. The following changes shall be made to the IECC:

1. Add Section C402.1.6 to read:

C402.1.6 Groups F, S, and U. Appendix CD may be used as an alternative to the building thermal envelope provisions of this code for Groups F, S, and U.

2. Add an exception to the first paragraph of Section C403.7.7 to read:

Exception: Where a grease duct serving a Type I hood is installed in accordance with IMC Section 506.3, motorized or gravity dampers shall not be installed.

3. Add Section C403.2.2.1 to read:

C403.2.2.1 Dwelling unit mechanical ventilation. Mechanical ventilation shall be provided for dwelling units in accordance with the IMC.

4. Delete Section C403.7.5 and Table C403.7.5.

5. Delete Sections C404.5 through C404.5.2.1, including Tables.

6. Change Section C405.4 to read:

C405.4 Exterior lighting. All exterior lighting, other than low-voltage landscape lighting, shall comply with Section C405.4.1.

Exception: Where approved because of historical, safety, signage, or emergency considerations.

7. Change Section C502.1 to read:

C502.1 General. Additions to an existing building, building system, or portion thereof shall conform to the provisions of Section 805 of the VEBC.

8. Delete Sections C502.2 through C502.3.6.2.

9. Change Section C503.1 to read:

C503.1 General. Alterations to any building or structure shall comply with the requirements of Chapter 6 of the VEBC.

10. Delete Sections C503.2 through C503.5.

11. Change Section C504.1 to read:

C504.1 General. Buildings, structures, and parts thereof shall be repaired in compliance with Section 510 of the VEBC.

12. Delete Section C504.2.

13. Add Appendix CD to read:

APPENDIX CD BUILDING ENVELOPE REQUIREMENTS.

D101 Scope.

CD101.1 General. These provisions shall be permitted as an alternative to building thermal envelope requirements for building areas containing uses that are classified as Group F, S or U.

CD102 Building Envelope Requirements.

CD102.1 Insulation and fenestration criteria. The building thermal envelope shall meet the requirements of Tables CD102.2(1) and CD102.3 based on the climate zone specified in Chapter 3 CE. Buildings with a vertical fenestration area or skylight area that exceeds that allowed in Table CD102.3 shall comply with the building envelope provisions of ASHRAE/IESNA 90.1.

CD102.2 Specific insulation requirements. Opaque assemblies shall comply with Table CD102.2(1).

CD102.2.1 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 CD102.2(1) based on construction materials used in the roof assembly.

Exception: Continuously insulated roof assemblies where the thickness of insulation varies one inch (25.4 mm) or less and where the area weighted U-factor is equivalent to the same assembly with the R-value specified in Table CD102.2(1).

Insulation installed on a suspended ceiling with removable ceiling tiles shall not be considered part of the minimum thermal resistance of the roof insulation.

CD102.2.2 Classification of walls. Walls associated with the building envelope shall be classified in accordance with Section CD102.2.2.1 or D102.2.2.2.

CD102.2.2.1 Above-grade walls. Above-grade walls are those walls covered by Section CD102.2.3 on the exterior of the building and completely above grade or walls that are more than 15 percent above grade.

CD102.2.2.2 Below-grade walls. Below-grade walls covered by Section CD102.2.4 are basement or first-story walls associated with the exterior of the building that are at least 85% below grade.

CD102.2.2.3 Above-grade walls. The minimum thermal resistance (R-value) of the insulating materials installed in the wall cavity between the framing members and continuously on the walls shall be as specified in Table CD102.2(1) based on framing type and construction materials used in the wall assembly. The R-value of integral insulation installed in concrete masonry units (CMU) shall not be used in determining compliance with Table CD102.2(1). "Mass walls" shall include walls weighing at least (i) 35 pounds per square foot (170 kg/m2) of wall surface area or (ii) 25 pounds per square foot (120 kg/m2) of wall surface area if the material weight is not more than 120 pounds per cubic foot (1,900 kg/m3).

CD102.2.4 Below-grade walls. The minimum thermal resistance (R-value) of the insulating material installed in or continuously on the below-grade walls shall be as specified in Table CD102.2(1) and shall extend to a depth of 10 feet I (3048 mm) below the outside finish ground level or to the level of the floor, whichever is less.

CD102.2.5 Floors over outdoor air or unconditioned space. The minimum thermal resistance (R-value) of the insulating material installed either between the floor framing or continuously on the floor assembly shall be as specified in Table CD102.2(1) based on construction materials used in the floor assembly.

"Mass floors" shall include floors weighing at least (i) 35 pounds per square foot (170 kg/m2) of floor surface area or (ii) 25 pounds per square foot (120 kg/m2) of floor surface area if the material weight is not more than 12 pounds per cubic foot (1,900 kg/m3).

CD102.2.6 Slabs on grade. The minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-grade floors shall be as specified in Table CD102.2(1). The insulation shall be placed on the outside of the foundation or on the inside of a foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as shown in the table or to the top of the footing, whichever is less, or downward to at least the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table.

CD102.2.7 Opaque doors. Opaque doors (doors having less than 50% glass area) shall meet the applicable requirements for doors as specified in Table CD102.2(1) and be considered as part of the gross area of above-grade walls that are part of the building envelope.

TABLE CD102.2(1) OPAQUE THERMAL ENVELOPE INSULATION COMPONENT MINIMUM REQUIREMENTS, R-VALUEa METHOD

CLIMATE ZONE

3

4 EXCEPT MARINE

5 AND MARINE 4

Roofs

Insulation entirely above roof deck

R-15ci

R-15ci

R-15ci

Metal buildings (with R-5 thermal blocksa)b

R-19

R-19

R-19

Attic and other

R-30

R-30

R-30

Walls, above grade

Mass

R-5.7cic, e

R-5.7cic

R-7.6ci

Metal buildingb

R-13

R-13

R-13 + R-13

Metal framed

R-13

R-13

R-13 + R-3.8ci

Wood framed and other

R-13

R-13

R-13

Walls, below grade

Below-grade walld

NR

NR

NR

Floors

Mass

R-5ci

R-10ci

R-10ci

Joist/framing

R-19

R-19

R-19

Slab-on-grade floors

Unheated slabs

NR

NR

NR

Heated slabs

R-7.5 for 12″ below

R-7.5 for 12″ below

R-7.5 for 24″ below

Opaque doors

Swinging

U - 0.70

U - 0.70

U - 0.70

Roll-up or sliding

U - 1.45

U - 1.45

U - 1.45

For SI: 1 inch = 25.4 mm

1 pound per square foot = 4.88 kg/m2

1 pound per cubic foot = 16 kg/m3

ci = Continuous Insulation

NR = No requirement

a. Thermal blocks are a minimum R-5 of rigid insulation which extends 1-inch beyond the width of the purlin on each side, perpendicular to the purlin.

b. Assembly description can be found in Table CD102.2(2).

c. R-5.7ci is allowed to be substituted with concrete block walls complying with ASTM C90, ungrouted or partially grouted at 32 inches or less on center vertically and 48 inches or less on center horizontally, with ungrouted cores filled with materials having a maximum thermal conductivity of 0.44 Btu-in/h-f2 °F.

d. Where heated slabs are below grade, below-grade walls shall comply with the exterior insulation requirements for perimeter insulation according to the heated slab-on-grade construction.

e. Insulation is not required for mass walls in Climate Zone 3A located below the "Warm-Humid" line, and in Zone 3B.

TABLE CD102.2(2) METAL BUILDING ASSEMBLY DESCRIPTIONS

ROOFS

DESCRIPTIONS

REFERENCE

R-19 + R-10

Filled cavity roof.

Thermal blocks are a minimum, R-5 of rigid insulation, which extends 1 inch beyond the width of the purlin on each side, perpendicular to the purlin.

ASHRAE/IESNA 90.1-2004

Table A2.3

R-19

Standing seam with single insulation layer.

Thermal blocks are a minimum R-5 of rigid insulation, which extends 1 inch beyond the width of the purlin on each side, perpendicular to the purlin.

This construction R-19 insulation batts draped perpendicularly over the purlins. Thermal blocks are then placed above the purlin/batt, and the roof deck is secured to the purlins.

ASHRAE/IESNA 90.1-2004

Table A2.3

Walls

R-13

Single insulation layer

The first layer of R-13 insulation batts is installed continuously perpendicular to the girts and is compressed as the metal skin is attached to the girts.

ASHRAE/IESNA 90.1-2004

Table A3.2

R-13 + R-13

Double insulation layer

The first layer of R-13 insulation batts is installed continuously perpendicular to the girts and is compressed as the metal skin is attached to the girts.

ASHRAE/IESNA 90.1-2004

Table A3.2

For SI: 1 inch = 25.4 mm.

CD102.3 Fenestration. Fenestration shall comply with Table CD102.3.

CD102.3.1 Maximum area. The vertical fenestration area (not including opaque doors) shall not exceed the percentage of the gross wall area specified in Table CD102.3. The skylight area shall not exceed the percentage of the gross roof area specified in Table CD102.3.

CD102.3.2 Maximum U-factor and solar heat gain coefficient (SHGC). For vertical fenestration, the maximum U-factor and solar heat gain coefficient (SHGC) shall be as specified in Table CD102.3 based on the window projection factor. For skylights, the maximum U-factor and SHGC shall be as specified in Table CD102.3.

The window projection factor shall be determined in accordance with Equation CD-1.

PF = A/B (Equation CD-1)

where:

PF = Projection factor (decimal).

A = Distance measured horizontally from the furthest continuous extremity of any overhang, eave, or permanently attached shading device to the vertical surface of the glazing.

B = Distance measured vertically from the bottom of the glazing to the underside of the overhang, eave, or permanently attached shading device.

Where different windows or glass doors have different PF values, they shall each be evaluated separately, or an area-weighted PF value shall be calculated and used for all windows and glass doors.

CD102.4 Air leakage.

CD102.4.1 Window and door assemblies. The air leakage of window and sliding or swinging door assemblies that are part of the building envelope shall be determined in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, or NFRC 400 by an accredited, independent laboratory and labeled and certified by the manufacturer and shall not exceed the values in Section C402.4.2 of the 2012 IECC.

Exception: Site-constructed windows and doors that are weatherstripped or sealed in accordance with Section CD102.4.3.

CD102.4.2 Curtain wall, storefront glazing, and commercial entrance doors. Curtain wall, storefront glazing, and commercial glazed swinging entrance doors and revolving doors shall be tested for air leakage at 1.57 pounds per square foot (psf) (75 Pa) in accordance with ASTM E 283. For curtain walls and storefront glazing, the maximum air leakage rate shall be 0.3 cubic foot per minute per square foot (cfm/ft2) (5.5 m3/h x m2) of fenestration area. For commercial glazed swinging entrance doors and revolving doors, the maximum air leakage shall be 1.00 cfm/ft2 (18.3 m3/h x m2) of door area when tested in accordance with ASTM E 283.

CD102.4.3 Sealing of the building envelope. Openings and penetrations in the building envelope shall be sealed with caulking materials or closed with gasketing systems compatible with the construction materials and location. Joints and seams shall be sealed in the same manner or taped or covered with a moisture vapor-permeable wrapping material. Sealing materials spanning joints between construction materials shall allow for expansion and contraction of the construction materials.

CD102.4.4 Outdoor air intakes and exhaust openings. Stair and elevator shaft vents and other outdoor air intakes and exhaust openings integral to the building envelope shall be equipped with not less than a Class I motorized, leakage-rated damper with a maximum leakage rate of four cfm per square foot (6.8 L/s – C m2) at 1.0 inch water gauge (w.g.) (1250 Pa) when tested in accordance with AMCA 500D.

Exception: Gravity (nonmotorized) dampers are permitted to be used in buildings less than three stories in height above grade.

CD102.4.5 Loading dock weather seals. Cargo doors and loading dock doors shall be equipped with weather seals to restrict infiltration when vehicles are parked in the doorway.

CD102.4.6 Vestibules. A door that separates conditioned space from the exterior shall be protected with an enclosed vestibule, with all doors opening into and out of the vestibule equipped with self-closing devices. Vestibules shall be designed so that in passing through the vestibule it is not necessary for the interior and exterior doors to open at the same time.

Exceptions:
1. Buildings in Climate Zones I and 2 as indicated in Figure C301.1 and Table C301.1.

2. Doors not intended to be used as a building entrance door, such as doors to mechanical or electrical equipment rooms.

3. Doors opening directly from a sleeping unit or dwelling unit.

4. Doors that open directly from a space less than 3,000 square feet (298 m2) in area.

5. Revolving doors.

6. Doors used primarily to facilitate vehicular movement or material handling and adjacent personnel doors.

TABLE CD102.3 BUILDING ENVELOPE REQUIREMENTS: FENESTRATION

CLIMATE ZONE

3

4 EXCEPT MARINE

5 AND MARINE 4

Vertical fenestration (40% maximum of above-grade wall)

U-factor

Framing materials other than metal with or without metal reinforcement or cladding

U-factor

0.65

0.40

0.35

Metal framing with or without thermal break

Curtain Wall/Storefront U-factor

0.60

0.50

0.45

Entrance Door U-factor

.90

.85

.80

All Other U-factora

.65

.55

.55

SHGC-All frame types

SHGC: PF < 0.25

.25

.40

.40

SHGC: 0.25 ≤ PF < 0.5

.33

NR

NR

SHGC ≥ 0.5

0.40

NR

NR

Skylights (3.0% maximum)

Glass

U-Factor

0.90

0.60

0.60

SHGC

0.40

0.40

0.40

Plastic

U-Factor

1.30

1.30

1.30

SHGC

0.35

0.62

0.62

NR = No requirement

PF = Projection factor (See Section CD102.3.2).

a. All others includes operable windows, fixed windows, and nonentrance doors.

CD102.4.7 Recessed luminaires. When installed in the building envelope, recessed luminaires shall meet one of the following requirements:

1. Type IC rated, manufactured with no penetrations between the inside of the recessed fixture and ceiling cavity and sealed or gasketed to prevent air leakage into the unconditioned space.

2. Type IC or non-IC rated, installed inside a sealed box constructed from a minimum 0.5-inch-thick (12.7 mm) gypsum wallboard or constructed from a preformed polymeric vapor barrier or other air-tight assembly manufactured for this purpose, while maintaining required clearances of not less than 0.5 inch (12.7 mm) from combustible material and not less than three inches (76 mm) from insulation material.

3. Type IC rated, in accordance with ASTM E 283 admitting no more than 2.0 cubic feet per minute (cfm) (0.944 L/s) of air movement from the conditioned space to the ceiling cavity. The luminaire shall be tested at 1.57 psf (75 Pa) pressure difference and shall be labeled.

CD102.5 Moisture control. All framed walls, floors, and ceilings not ventilated to allow moisture to escape shall be provided with an approved vapor retarder having a permeance rating of one perm (5.7 x 10-11 kg/Pa· s · m2) or less when tested in accordance with the dessicant method using Procedure A of ASTM E 96. The vapor retarder shall be installed on the warm-in-winter side of the insulation.

Exceptions:
1. Buildings located in Climate Zones 1 through 3 as indicated in Figure C301.1 and Table C301.1.

2. In construction where moisture or its freezing will not damage the materials.

3. Where other approved means to avoid condensation in unventilated framed wall, floor, roof, and ceiling cavities are provided.

14. Add an exception to Section R401.3 to read:

Exception: Where approved, certificates for multi-family dwelling units shall be permitted to be located off-site at an identified location.

15. Change the wood frame wall R-value categories for Climate Zones 3A, 4A, and 5A in Table R402.1.3 to read:

Wood Frame Wall R-Value

15 or 13+1h

16. Change the frame wall U-factor categories for Climate Zones 3A, 4A, and 5A in Table R402.1.2 to read:

Frame Wall U-Factor

0.079

17. Change Section R402.2.4 to read:

R402.2.4 Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces (e.g., attics and crawl spaces) shall be weatherstripped and insulated in accordance with the following values:

1. Hinged vertical doors shall have a minimum overall R-5 insulation value;

2. Hatches and scuttle hole covers shall be insulated to a level equivalent to the insulation on the surrounding surfaces; and

3. Pull down stairs shall have a minimum of 75% of the panel area having R-5 rigid insulation.

Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood framed or equivalent baffle or retainer is required to be provided when loose fill insulation is installed, the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened and to provide a permanent means of maintaining the installed R-value of the loose fill insulation.

18. Change the title of the "Insulation Installation Criteria" category of Table R402.4.1.1; change the "Shower/tub on exterior wall" category of Table R402.4.1.1, and add footnotes "c" and "d" to Table R402.4.1.1 to read:

Component

Air Barrier Criteria

Insulation Installation Criteria d

Shower/tub on exterior wallc

The air barrier installed at exterior walls adjacent to showers and tubs shall be installed on the interior side and separate the exterior walls from the showers and tubs.

Exterior walls adjacent to showers and tubs shall be insulated.

c. Air barriers used behind showers and tubs on exterior walls shall be of a permeable material that does not cause the entrapment of moisture in the stud cavity.

d. Structural integrity of headers shall be in accordance with the applicable building code.

19. Change Section R402.4.1.2 to read:

R402.4.1.2 Testing. The building or dwelling unit shall be tested and verified as having an air leakage rate not exceeding five air changes per hour in Climate Zone 4. Testing shall be conducted in accordance with RESNET/ICC 380, ASTM E 779, or ASTM E 1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). A written report of the results of the test shall be signed by the party conducting the test and provided to the building official. Testing shall be conducted by a Virginia licensed general contractor, a Virginia licensed HVAC contractor, a Virginia licensed home inspector, a Virginia registered design professional, a certified BPI Envelope Professional, a certified HERS rater, or a certified duct and envelope tightness rater. The party conducting the test shall have been trained on the equipment used to perform the test. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.

Note: Should additional sealing be required as a result of the test, consideration may be given to the issuance of a temporary certificate of occupancy in accordance with Section 116.1.1.

During testing:

1. Exterior windows and doors and fireplace and stove doors shall be closed, but not sealed beyond the intended weatherstripping or other infiltration control measures;

2. Dampers, including exhaust, intake, makeup air, backdraft, and flue dampers, shall be closed, but not sealed beyond intended infiltration control measures;

3. Interior doors, if installed at the time of the test, shall be open;

4. Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed;

5. Heating and cooling systems, if installed at the time of the test, shall be turned off; and

6. Supply and return registers, if installed at the time of the test, shall be fully open.

20. Change Section R402.4.1.3 to read:

R402.4.1.3 Leakage rate: When complying with Section R401.2.1, the building or dwelling unit shall have an air leakage rate not exceeding 5.0 air changes per hour in Climate Zones 3 through 5 when tested in accordance with Section R402.4.1.2.

21. Add Section R403.1.3 to read:

R403.1.3 Heat pump as primary space heat source. Electric resistance heat shall not be used as the primary heat source for electric space heating if a ducted or ductless heat pump can be installed. Electric resistance space heating may be used for defrost, supplemental, or emergency heat, A heat pump shall be designed so that, except during defrost or emergency heating modes, supplemental heating does not energize unless the outdoor temperature is below 40ºF (4ºC).

22. Change the last paragraph of Section R403.3.5 to read:

A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. The licensed mechanical contractor installing the mechanical system shall be permitted to perform the duct testing. The contractor shall have been trained on the equipment used to perform the test.

23. Change Section R403.3.7 to read:

(R403.3.7) Building cavities. Building framing cavities used as ducts or plenums shall comply with VRC Section M1601.1.1.

24. Change Section R403.7 to read:

R403.7 Equipment and appliance sizing. Heating and cooling equipment and appliances shall be sized in accordance with ACCA Manual S or other approved sizing methodologies based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies.

Exception: Heating and cooling equipment and appliance sizing shall not be limited to the capacities determined in accordance with Manual S or other approved sizing methodologies where any of the following conditions apply:

1. The specified equipment or appliance utilizes multi-stage technology or variable refrigerant flow technology and the loads calculated in accordance with the approved heating and cooling methodology fall within the range of the manufacturer's published capacities for that equipment or appliance.

2. The specified equipment or appliance manufacturer's published capacities cannot satisfy both the total and sensible heat gains calculated in accordance with the approved heating and cooling methodology and the next larger standard size unit is specified.

3. The specified equipment or appliance is the lowest capacity unit available from the specified manufacturer.

25. Change Section R406.3.2 to read:

Section N1106.3.2 (R406.3.2) Onsite renewables are included. When onsite renewable energy is included for compliance using the Energy Rating Index (ERI) analysis per Section N1106.4 (R406.4), the building thermal envelope shall be greater than or equal to levels of energy efficiency and solar heat gain coefficient in Table N1102.1.2 (R402.1.2), with a ceiling U-factor of 0.026 and a frame wall U-factor of 0.060, or Table N1102.1.3 (R402.1.3), with a ceiling R-value of 49 and a wood frame wall R-value of 20 or 13+5.

26. Change Section R501.1 to read:

R501.1 Scope. The provisions of the Virginia Existing Building Code shall control the alteration, repair, addition, and change of occupancy of existing buildings and structures.

27. Delete Sections R501.1.1 through R501.6.

28. Change Section R502.1 to read:

R502.1 General. Additions to an existing building, building system, or portion thereof shall conform to the provisions of Section 805 of the VEBC.

29. Delete Sections R502.2 through R502.3.4.

30. Change Section R503.1 to read:

R503.1 General. Alterations to any building or structure shall comply with the requirements of Chapter 6 of the VEBC.

31. Delete Sections R503.1.1 through R503.1.4.

32. Change Section R504.1 to read:

R504.1 General. Buildings, structures, and parts thereof shall be repaired in compliance with Section 507 of the VEBC.

33. Delete Section R504.2.

Statutory Authority

§ 36-98 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 27, Issue 2, eff. March 1, 2011; Change in Effective Date, 27:5 VA.R. 534 November 8, 2010; amended, Virginia Register Volume 30, Issue 16, eff. July 14, 2014; Volume 34, Issue 18, eff. September 4, 2018; Volume 37, Issue 14, eff. July 1, 2021; Volume 40, Issue 9, eff. January 18, 2024.

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