Chapter 8 — COMPLIANCE FORMS, WORKSHEETS AND REFERENCE MATERIAL

Section A6.205 — [OSHPD 1 & 4]—BUILDING ENVELOPE

2025 California Green Building Standards Code (Title 24, Part 11) · 2025 edition · updated 2026-07-25 · California

A6.205.1 Fenestration products and exterior doors.

A6.205.1.1 Certification of fenestration products and exterior doors other than field-fabricated. Any fenestration product and exterior door, other than field-fabricated fenestration products and field-fabricated exterior doors, may be installed only if the manufacturer has certified to the California Energy Commission or if an independent certifying organization approved by the Commission has certified that the product complies with all of the applicable requirements of this subsection.

A6.205.1.1.1 Air leakage. Manufactured fenestration products and exterior doors shall have air infiltration rates not exceeding 0.3 cfm/ft [2] of window area, 0.3 cfm/ft [2] of door area for residential doors, 0.3 cfm/ft [2] of door area for nonresidential single doors

APPENDIX A6.1-4 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

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APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

(swinging and sliding) and 1.0 cfm/ft [2] for nonresidential double doors (swinging), when tested according to NFRC-400 or ASTM E283 at a pressure differential of 75 pascals (or 1.57 pounds/ft [2] ), incorporated herein by reference.

A6.205.1.1.2 U -factor. A fenestration product’s U -factor shall be rated in accordance with NFRC 100 or the applicable default U -factor set forth in Table A.5.205.1-A.

Exception: If the fenestration product is a skylight or is site-built fenestration in a building covered by the nonresidential standards with less than 10,000 square feet of site-built fenestration, the default U- factor may be calculated as set forth in Reference Nonresidential Appendix NA6 of the California Energy Commission 2008 Building Energy Efficiency Standards for Residential and Nonresidential Buildings.

stration product is a skylight or is site-built fenestration in a building covered by the nonresidential standards with less than 10,000 square feet of site-built fenestration, the default U- factor may be calculated as set forth in Reference Nonresidential Appendix NA6 of the California Energy Commission 2008 Building Energy Efficiency Standards for Residential and Nonresidential Buildings.

TABLE A.5.205.1-A—DEFAULT FENESTRATION PRODUCT U-FACTORS

FRAME	PRODUCT TYPE	SINGLE PANE U-FACTOR	DOUBLE PANE1 U-FACTOR	GLASS BLOCK2 U-FACTOR
Metal	Operable	1.28	0.79	0.87
Metal	Fixed	1.19	0.71	0.72
Metal	Greenhouse/garden window	2.26	1.40	N.A.
Metal	Doors	1.25	0.77	N.A.
Metal	Skylight	1.98	1.30	N.A.
Metal, thermal break	Operable	N.A.	0.66	N.A.
Metal, thermal break	Fixed	N.A.	0.55	N.A.
Metal, thermal break	Greenhouse/garden window	N.A.	1.12	N.A.
Metal, thermal break	Doors	N.A.	0.59	N.A.
Metal, thermal break	Skylight	N.A.	1.11	N.A.
Nonmetal	Operable	0.99	0.58	0.60
Nonmetal	Fixed	1.04	0.55	0.57
Nonmetal	Greenhouse/garden window	0.99	0.53	N.A.
Nonmetal	Doors	1.94	1.06	N.A.
Nonmetal	Skylight	1.47	0.84	N.A.
N.A. = Not applicable. 1. For all dual-glazed fenestration products, adjust the listed_U_-factors as follows: a. Add 0.05 for products with dividers between panes if spacer is less than7/16 inch wide. b. Add 0.05 to any product with true divided lite (dividers through the panes). 2. Translucent or transparent panels shall use glass blocks.

A6.205.1.1.3 SHGC. A fenestration product’s SHGC shall be rated in accordance with NFRC 200 for site-built fenestration or use the applicable default SHGC set forth in Table A6.205.1-B.

Exception: If the fenestration product is a skylight or is site-built fenestration in a building covered by the nonresidential standards with less than 10,000 square feet of site-built fenestration, the default SHGC may be calculated as set forth in Reference Nonresidential Appendix NA6 of the California Energy Commission 2008 Building Energy Efficiency Standards for Residential and Nonresidential Buildings.

TABLE A.5.205.1-B—DEFAULT SOLAR HEAT GAIN COEFFICIENT (SHGC)

FRAME	PRODUCT TYPE	GLAZING	TOTAL WINDOW SHGC	TOTAL WINDOW SHGC	TOTAL WINDOW SHGC
FRAME	PRODUCT TYPE	GLAZING	Single Pane	Double Pane	Glass Block1
Metal	Operable	Clear	0.80	0.70	0.70
Metal	Fixed	Clear	0.83	0.73	0.73
Metal	Operable	Tinted	0.67	0.59	N.A.
Metal	Fixed	Tinted	0.68	0.60	N.A.
Metal, thermal break	Operable	Clear	N.A.	0.63	N.A.
Metal, thermal break	Fixed	Clear	N.A.	0.69	N.A.
Metal, thermal break	Operable	Tinted	N.A.	0.53	N.A.
Metal, thermal break	Fixed	Tinted	N.A.	0.57	N.A.
Nonmetal	Operable	Clear	0.74	0.65	0.70
Nonmetal	Fixed	Clear	0.76	0.67	0.67
Nonmetal	Operable	Tinted	0.60	0.53	N.A.
Nonmetal	Fixed	Tinted	0.63	0.55	N.A.
N.A. = Not applicable. 1. Translucent or transparent panels shall use glass block values.

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APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

A6.205.1.1.4 Labeling. Fenestration products shall:

Have a temporary label (or label certificate for site- built fenestration) meeting the requirements of Section 10111(a)1 of Title 24, Part 1 not to be removed before inspection by the enforcement agency, listing the certified U factor and SHGC and certifying that the air leakage requirements of Section A6.205.1.1.1 are met for each product line; and
Have a permanent label (or label certificate for site-built fenestration) meeting the requirements of Section 10111(a)2 of Title 24, Part 1 if the product is rated using NFRC procedures.

removed before inspection by the enforcement agency, listing the certified U factor and SHGC and certifying that the air leakage requirements of Section A6.205.1.1.1 are met for each product line; and 2. Have a permanent label (or label certificate for site-built fenestration) meeting the requirements of Section 10111(a)2 of Title 24, Part 1 if the product is rated using NFRC procedures.

A6.205.1.1.5 Fenestration acceptance requirements. Before an occupancy permit is granted, site-built fenestration products in other than low-rise residential buildings shall be certified as meeting the Acceptance Requirements for Code Compliance, as specified by the Reference Nonresidential Appendix NA7 of the California Energy Commission 2008 Building Energy Efficiency Standards for Residential and Nonresidential Buildings to ensure that site-built fenestration meet Standards requirements, including a matching label certificate for each product installed and be readily accessible at the project location. A Certificate of Acceptance shall be submitted to the enforcement agency that certifies that the fenestration product meets the acceptance requirements.

Exception: Fenestration products removed and reinstalled as part of a building alteration or addition.

A6.205.1.2 Installation of field-fabricated fenestration and exterior doors. Field-fabricated fenestration and field-fabricated exterior doors may be installed only if the compliance documentation has demonstrated compliance for the installation using U factors from Table A6.205.1-A and SHGC values from Table A6.205.1-B. Field-fabricated fenestration and field-fabricated exterior doors shall be caulked between the fenestration products or exterior door and the building and shall be weatherstripped.

Exception: Unframed glass doors and fire doors need not be weatherstripped or caulked.

A6.205.2 Joints and other openings. Joints and other openings in the building envelope that are potential sources of air leakage shall be caulked, gasketed, weatherstripped or otherwise sealed to limit infiltration and exfiltration.

A6.205.3 Insulation and roofing products.

A6.205.3.1 Certification by manufacturers. Any insulation shall be certified by Department of Consumer Affairs, Bureau of Household Good and Services that the insulation conductive thermal performance is approved pursuant to the California Code of Regulations, Title 24, Part 12, Chapters 12-13, Article 3,“Standards for Insulating Material.”

A6.205.3.2 Installation of urea formaldehyde foam insulation. Urea formaldehyde foam insulation may be applied or installed only if:

It is installed in exterior side walls; and
A four-mil-thick plastic polyethylene vapor barrier or equivalent plastic sheathing vapor barrier is installed between the urea formaldehyde foam insulation and the interior space in all applications.

A6.205.3.3 Flame spread rating. All insulating material shall be installed in compliance with the flame spread rating and smoke density requirements of the Title 24, Part 2, California Building Code.

A6.205.3.4 Installation of insulation in existing buildings. Insulation installed in an existing attic or on an existing duct or water heater, shall comply with the applicable requirements of Subsections A6.205.3.4.1, A6.205.3.4.2 and A6.205.3.4.3 below. If a contractor installs the insulation, the contractor shall certify to the customer, in writing, that the insulation meets the applicable requirements of Subsections A6.205.3.4.1, A6.205.3.4.2 and A6.205.3.4.3 below.

A6.205.3.4.1 Attics. If insulation is installed in the existing attic of a low-rise residential building, the R-value of the total amount of insulation (after addition of insulation to the amount, if any, already in the attic) shall be at least R-38 in climate zones 1 and 16; and R-30 in all other climate zones.

Exception: Where the accessible space in the attic is not large enough to accommodate the required R-value, the entire accessible space shall be filled with insulation provided such installation does not violate Section 1203.2 of Title 24, Part 2, California Building Code.

A6.205.3.4.2 Water heaters. If external insulation is installed on an existing unfired water storage tank or on an existing backup tank for a solar water-heating system, it shall have an R -value of at least R-12 or the heat loss of the tank surface based on an 80°F water-air temperature difference shall be less than 6.5 Btu per hour per square foot.

A6.205.3.4.3 Ducts. If insulation is installed on an existing space-conditioning duct, it shall comply with Section 605 of the California Mechanical Code (CMC).

A6.205.3.5 Placement of roof/ceiling insulation. Insulation installed to limit heat loss and gain through the top of conditioned spaces shall comply with the following:

A6.205.3.5.1 Insulation shall be installed in direct contact with a continuous roof or ceiling which is sealed to limit infiltration and exfiltration as specified in Section A6.205.2, including but not limited to placing insulation either above or below the roof deck or on top of a drywall ceiling; and

A6.205.3.5.2 When insulation is installed at the roof in nonresidential buildings, fixed vents or openings to the outdoors or to unconditioned spaces shall not be installed and the space between the ceiling and the roof is either directly or indirectly conditioned space and shall not be considered an attic for the purposes of complying with CBC attic ventilation requirements; and

APPENDIX A6.1-6 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

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APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

A6.205.3.5.3 Insulation placed on top of a suspended ceiling with removable ceiling panels shall be deemed to have no affect on envelope heat loss; and

Exception: When there are conditioned spaces with a combined floor area no greater than 2,000 square feet in an otherwise unconditioned building and when the average height of the space between the ceiling and the roof over these spaces is greater than 12 feet, insulation placed in direct contact with a suspended ceiling with removable ceiling panels shall be an acceptable method of reducing heat loss from a conditioned space and shall be accounted for in heat loss calculations.

A6.205.3.5.4 Insulation shall be installed below the roofing membrane or layer used to seal the roof from water penetration unless the insulation has a maximum water absorption of 0.3 percent by volume when tested according to ASTM C272.

Note: Vents, which do not penetrate the roof deck, that are designed for wind resistance for roof membranes are not within the scope of Section A6.205.3.5.2.

A6.205.3.6 Demising walls in nonresidential buildings. The opaque portions of framed demising walls in nonresidential buildings shall be insulated with an installed R -value of no less than R-13 between framing members.

A6.205.3.7 Insulation requirements for heated slab floors. Heated slab-on-grade floors shall be insulated according to the requirements in Table A6.205.3-A.

TABLE A6.205.3-A—SLAB INSULATION REQUIREMENTS FOR HEATED SLAB-ON-GRADE

INSULATION LOCATION	INSULATION ORIENTATION	INSTALLATION REQUIREMENTS	CLIMATE ZONE	INSULATION R-FACTOR
Outside edge of heated slab, either inside or outside the foundation wall	Vertical	From the level of the top of the slab, down 16 inches or to the frost line, whichever is greater. Insulation may stop at the top of the footing where this is less than the required depth. For below grade slabs, vertical insu- lation shall be extended from the top of the foundation wall to the bottom of the foundation (or the top of the footing) or to the frost line, whichever is greater.	1 – 15	5
Outside edge of heated slab, either inside or outside the foundation wall	Vertical	From the level of the top of the slab, down 16 inches or to the frost line, whichever is greater. Insulation may stop at the top of the footing where this is less than the required depth. For below grade slabs, vertical insu- lation shall be extended from the top of the foundation wall to the bottom of the foundation (or the top of the footing) or to the frost line, whichever is greater.	16	10
Between heated slab and outside founda- tion wall	Vertical and Horizontal	Vertical insulation from top of slab at inside edge of outside wall down to the top of the horizontal insulation. Horizontal insulation from the outside edge of the vertical insulation extending 4 feet toward the center of the slab in a direction normal to the outside of the building in plan view.	1 – 15	5
Between heated slab and outside founda- tion wall	Vertical and Horizontal	Vertical insulation from top of slab at inside edge of outside wall down to the top of the horizontal insulation. Horizontal insulation from the outside edge of the vertical insulation extending 4 feet toward the center of the slab in a direction normal to the outside of the building in plan view.	16	10 vertical and 7 horizontal

A6.205.3.7.1 Insulation materials in ground contact must:

A6.205.3.7.1.1 Comply with the certification requirements of Section A6.205.3.1; and

A6.205.3.7.1.2 Have a water absorption rate for the insulation material alone without facings that is no greater than 0.3 percent when tested in accordance with Test Method A – 24 Hour-Immersion of ASTM C272.

A6.205.3.7.2 Insulation installation must:

A6.205.3.7.2.1 Cover the insulation with a solid guard that protects against damage from ultraviolet radiation, moisture, landscaping operation, equipment maintenance and wind; and

A6.205.3.7.2.2 Include a rigid plate, which penetrates the slab and blocks the insulation from acting as a conduit for insects from the ground to the structure above the foundation.

A6.205.3.8 Wet insulation systems. When insulation is installed on roofs above the roofing membrane or layer used to seal the roof from water penetration, the effective R-value of the insulation shall be as specified in Reference Joint Appendix JA4 of the California Energy Commission 2008 Building Energy Efficiency Standards for Residential and Nonresidential Buildings.

A6.205.3.9 Roofing products solar reflectance and thermal emittance.

A6.205.3.9.1 In order to meet the requirements of Sections 141, 142, 143(a)1, 149(b)1B, 151(f)12, 152(b)1H or 152(b)2 of Title 24, Part 6, a roofing product’s thermal emittance and 3-year aged solar reflectance shall be certified and labeled according to the requirements of Section 10-113 of Title 24, Part 1.

Exception: Roofing products that are not certified according to Section 10-113 of Title 24, Part 1 shall assume the following default aged reflectance/emittance values:

A6.205.3.9.1.1 For asphalt shingles, 0.08/0.75

A6.205.3.9.1.2 For all other roofing products, 0.10/ 0.75

A6.205.3.9.2 If CRRC testing for 3-year aged reflectance is not available for any roofing products, the 3-year aged value shall be derived from the CRRC initial value using the equation R aged = [0.2 + 0.7[ρ initial –0.2], where ρ initial = the initial Solar Reflectance. A6.205.3.9.3 Solar Reflectance Index (SRI), calculated as specified by ASTM E1980-01, may be used as an alternative to thermal emittance and 3-year aged solar reflectance when complying with the requirements of Sections 141, 142, 143(a)1, 149(b)1B, 151(f)12, 152(b)1H or 152(b)2 of Title 24, Part 6. SRI calculations shall be based on moderate wind velocity of 2-6 meters per second. The SRI shall be calculated based on the 3-year aged reflectance value of the roofing products.

A6.205.3.9.4 Liquid applied roof coatings applied to low-sloped roofs in the field as the top surface of a roof covering shall:

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APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]

A6.205.3.9.4.1 Be applied across the entire roof surface to meet the dry mil thickness or coverage recommended by the coating manufacturer, taking into consideration the substrate on which the coating is applied, and

A6.205.3.9.4.2 Meet the minimum performance requirements listed in Table A6.205.3-B or the minimum performance requirements of ASTM C836, D3468, D6083 or D6694, whichever are appropriate to the coating material.

Exceptions:

Aluminum-pigmented asphalt roof coatings shall meet the requirements of ASTM D2824 or ASTM D6848 and be installed as specified by ASTM D3805.
Cement-based roof coatings shall contain a minimum of 20 percent cement and shall meet the requirements of ASTM C1583, ASTM D822 and ASTM D5870.

TABLE A6.205.3-B—MINIMUM PERFORMANCE REQUIREMENTS FOR LIQUID APPLIED ROOF COATINGS

PHYSICAL PROPERTY	ASTM TEST PROCEDURE	REQUIREMENT
Initial percent elongation (break)	D2370	Minimum 200 percent 73ºF (23ºC)
Initial percent elongation (break) OR Initial flexibility	D2370 D522, Test B	Minimum 60 percent 0ºF (-18ºC) Minimum pass 1″ mandrel 0ºF (-18ºC)
Initial tensile strength (maximum stress)	D2370	Minimum 100 psi (1.38 Mpa) 73ºF (23ºC)
Initial tensile strength (maximum stress) OR Initial flexibility	D2370 D522, Test B	Minimum 200 psi (2.76 Mpa) 0ºF (-18ºC) Minimum pass 1″ mandrel 0ºF (-18ºC)
Final percent elongation (break) after accelerated weathering 1000 h	D2370	Minimum 100 percent 73ºF (23ºC)
Final percent elongation (break) after accelerated weathering 1000 h OR Flexibility after accelerated weathering 1000 h	D2370	Minimum 40 percent 0ºF (-18ºC) Minimum pass 1″ mandrel 0ºF (-18ºC)
Permeance	D1653	Maximum 50 perms
Accelerated weathering 1000 h	D4798	No cracking or checking1
1. Any cracking or checking visible to the eye fails the test procedure.

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▸ Contents — 2025 California Green Building Standards Code (Title 24, Part 11)

2025 California Green Building Standards Code (Title 24, Part 11)