Title 24 · California Energy Code

Default ratings, window film, and acceptance values for un‑rated fenestration

Q: When can I use a manufacturer NFRC label instead of defaults?

Use the manufacturer’s NFRC 100/200 label whenever it exists. The code prefers rated values; defaults only apply when an NFRC rating is not available. § 110.6 explains the preference for NFRC ratings.

Q: If I add aftermarket film with an NFRC label, can I model the combined window+film performance?

Yes — if the film/window combination is NFRC‑rated and labeled (or the manufacturer supplies an NFRC label for the assembled product), use the rated values. If the film is not NFRC‑rated, use the table defaults.

Q: Do I always add +0.05 for muntins or grid dividers?

Add +0.05 to the listed U‑factor for dual‑glazed products with dividers between panes if the spacer is less than 7/16 inch , and add +0.05 for any product that is a true divided lite — this is required by the table notes to Table 110.6‑A .

Q: How do I show compliance for site‑built fenestration?

For qualifying site‑built fenestration you may calculate default values per NA6 or use the table defaults (see exceptions in § 150.1(c)3A and § 110.6 notes). You must also meet acceptance requirements before occupancy for non‑single‑family buildings.

Q: Where is VT calculated if there is no NFRC VT label?

The code directs you to compute VT using the Reference Nonresidential Appendix NA6 when VT is not NFRC‑rated. This is in the table notes to the default tables.

If a window, skylight, or applied film has no NFRC rating, the California Energy Code requires you to use the default U‑factor and SHGC from Table 110.6‑A and 110.6‑B (and follow the table notes for adjustments such as +0.05 for true divided lites or narrow spacers, and to compute VT using NA6). See § 110.6 and the exceptions in § 150.1 for when the NA6 calculation is allowed.

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Last reviewed: July 6, 2026

What the code requires — plain English

If a fenestration product or applied window film is not rated by NFRC, the builder must use the default U‑factor and SHGC values in the code tables (Table 110.6‑A and Table 110.6‑B) and follow the table notes for adjustments and calculation of VT and other values, per § 110.6.

Short version: manufacturers’ NFRC labels are preferred. When a product or film has no NFRC rating (including many site‑built units or aftermarket films that are not NFRC‑rated), you must use the code’s default values and apply the table notes/adjustments in § 110.6.

Requirements in detail

Governing sections and defined terms (first mention)

§ 110.6 — default fenestration product U‑factors and SHGC (Tables 110.6‑A and 110.6‑B) and table notes that control how defaults are used.
§ 150.1(c)3A — prescriptive residential fenestration limits; allows use of default tables for unrated site‑built glazing under the dwelling exceptions.
NFRC 100 / NFRC 200 — the rating procedures referenced by the code for U‑factor and SHGC (when available).

What the tables and notes require (key items)

Use the NFRC rating if the product is tested and labeled. If not, use the applicable default values in Table 110.6‑A (default U‑factors) and Table 110.6‑B (default SHGC). Windows with window film not rated by NFRC must use the table defaults (i.e., film effects are represented by the default table entry).
For Visible Transmittance (VT) where not NFRC‑rated, calculate VT using the Reference Nonresidential Appendix NA6 as directed in the table notes.
Adjust default values for construction details: for dual‑glazed products add +0.05 to the listed U‑factor for (a) spacers less than 7/16 inch and (b) true divided lite (dividers through the glass). These adjustment rules are in the table notes to Table 110.6‑A.
Field‑fabricated or site‑built fenestration may only be installed when compliance documentation demonstrates compliance using Table 110.6‑A and Table 110.6‑B values (see § 110.6(b)).

Decision‑relevant summary table

Decision element	Typical default value (example)	When to use it	Code Reference
Default U‑factor — Nonmetal, fixed, double‑pane	0.55	Use when product is not NFRC 100 rated (or for eligible site‑built units using defaults)	§ 110.6 Table 110.6‑A
Default U‑factor — Metal frame, operable, double‑pane	0.79	Same as above	§ 110.6 Table 110.6‑A
Default SHGC — Nonmetal, fixed, double‑pane	0.67	Use when product or film not NFRC 200 rated	§ 110.6 Table 110.6‑B
Default SHGC — Metal frame, operable, double‑pane	0.70	Use when product or film not NFRC 200 rated	§ 110.6 Table 110.6‑B
Adjustment for true divided lite or spacer < 7/16 in	+0.05 to listed U‑factor	Apply to dual‑glazed products per table notes	§ 110.6 Table notes (Table 110.6‑A)
Window film not NFRC‑rated	Use table defaults for the product (do not model film separately)	Table note explicitly requires this	§ 110.6 table notes (Table 110.6‑A/B)
VT when not rated	Calculate using Reference Nonresidential Appendix NA6	Table note instructs this method	§ 110.6 table notes

(These values are pulled directly from the default tables; see the code tables for full lists of product/frame/glazing combinations.)

How window film is handled

If the window film is NFRC‑rated (i.e., has an NFRC 100/200 label), use the rated values. If the film (or the combination film+window) is not rated by NFRC, then the code directs you to use the default table values rather than invent a custom SHGC/U‑factor. This is stated in the table notes to Tables 110.6‑A and 110.6‑B.
In other words, aftermarket film without NFRC certification is treated as "un‑rated" and therefore modeled with the default fenestration product values in the tables.

Exceptions & special cases

Skylights and small site‑built glazed areas: specific exceptions allow calculation per Reference Appendix NA6 instead of using the table defaults for limited skylight/site‑built area; see the exceptions in § 110.6(a) and § 150.1(c)3A.
Chromogenic (dynamic) glazing: where used, the lower labeled U‑factor and SHGC is applied and chromogenic glazing must be treated separately (no area‑weighted averaging with non‑chromogenic glazing) per the § exceptions. See § 150.1(c)3A and related exception language.
Field‑fabricated fenestration: may be installed only if compliance documentation demonstrates the installation meets the code using Table 110.6‑A/B defaults (and they must be caulked/weatherstripped as required) — see § 110.6(b).
Tubular daylighting devices: VT for tubular devices is rated under NFRC 203 or computed per NA6 when allowed — see table notes and § 110.6(a)4.

Common mistakes

Treating aftermarket film that has no NFRC performance label as if it can be modeled with a custom, improved SHGC — the code requires use of default table values when the film is not NFRC‑rated.
Forgetting to add +0.05 to the default U‑factor for true divided lites or narrow spacers (< 7/16 in). That small adjustment is explicit in the table notes.
Using VT from the product label when the product is unrated (code requires NA6 calculation for VT when NFRC VT is not available).
Averaging chromogenic glazing with other windows when the code forbids area‑weighted averaging for chromogenic types. Refer to the chromogenic exception in § 150.1(c).

Worked example — concrete numbers

Scenario: A contractor installs a nonmetal, fixed, double‑pane window (single product, 15 ft²) and applies an aftermarket solar film that is not NFRC rated.

The product and the film are unrated; per the table notes you must use the default values from Table 110.6‑A and Table 110.6‑B (do not attempt to estimate film performance).
From Table 110.6‑A the default U‑factor for nonmetal, fixed, double‑pane is 0.55. From Table 110.6‑B the default SHGC for nonmetal, fixed, double‑pane is 0.67. Use those for code compliance calculations.
If the installed unit were a true divided‑lite dual‑glazed product, add +0.05 to the U‑factor: 0.55 + 0.05 = 0.60. Apply that adjusted U‑factor in the area‑weighted calculations.
VT: because neither product nor film is NFRC‑rated, compute VT per Reference NA6 as directed by the table notes (do not use an assumed VT).

Code references used in the example: § 110.6 (tables and table notes) and the exception language for unrated site‑built fenestration in § 150.1(c)3A when applicable.

Related provisions

§ 110.6(a) — certification, U‑factor, SHGC and VT rating requirements; table notes and acceptance requirements.
§ 110.6(b) — installation and documentation rules for field‑fabricated fenestration (use of default tables).
§ 150.1(c)3A — residential fenestration prescriptive limits and exceptions (use of defaults for unrated site‑built glazing).
Table 110.6‑A — Default fenestration product U‑factors (table and notes).
Table 110.6‑B — Default fenestration product SHGC (table and notes).
Reference Nonresidential Appendix NA6 — VT calculation method and site‑built fenestration calculations where allowed.

Code references

Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:

§ 0.05 High relevance — show source text

Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|

TABLE 110.6-B—DEFAULT SOLAR HEAT GAIN COEFFICIENT (SHGC)	Col2	Col3	Col4	Col5	Col6
FRAME TYPE	PRODUCT	GLAZING	FENESTRATION PRODUCT SHGC	FENESTRATION PRODUCT SHGC	FENESTRATION PRODUCT SHGC
FRAME TYPE	PRODUCT	GLAZING	Single Pane2, 3 SHGC	Double Pane2, 3 SHGC	Glass Block1, 2 SHGC
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	NA
Metal	Fixed	Tinted	0.68	0.60	NA
Metal, thermal break	Operable	Clear	NA	0.63	NA
Metal, thermal break	Fixed	Clear	NA	0.69	NA
Metal, thermal break	Operable	Tinted	NA	0.

§ 0.59 High relevance — show source text
12|NA| |Metal, thermal break|Glazed doors|NA|0.59|NA| |Metal, thermal break|Skylight|NA|1.11|NA| |Nonmetal|Operable|0.99|0.58|0.60| |Nonmetal|Fixed|1.04|0.55|0.57| |Nonmetal|Greenhouse/garden window|0.99|0.53|NA| |Nonmetal|Glazed doors|1.94|1.06|NA| |Nonmetal|Skylight|1.47|0.84|NA| |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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|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 block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|1. For all dual-glazed fenestration products, adjust the listed_U_-factors as follows:
a.

§ 0.05 High relevance — show source text

Add 0.05 to any product with true divided lite (dividers through the panes).
2. Translucent or transparent panels shall use glass block values when not rated by NFRC 100.
3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.|

TABLE 110.6-B—DEFAULT SOLAR HEAT GAIN COEFFICIENT (SHGC)	Col2	Col3	Col4	Col5	Col6
FRAME TYPE	PRODUCT	GLAZING	FENESTRATION PRODUCT SHGC	FENESTRATION PRODUCT SHGC	FENESTRATION PRODUCT SHGC
FRAME TYPE	PRODUCT	GLAZING	Single Pane2, 3 SHGC	Double Pane2, 3 SHGC	Glass Block1, 2 SHGC
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	NA
Metal	Fixed	Tinted	0.68	0.60	NA
Metal, thermal break	Operable	Clear	NA	0.63	NA
Metal, thermal break	Fixed	Clear	NA	0.69	NA
Metal, thermal break	Operable	Tinted	NA	0.53	NA
Metal, thermal break	Fixed	Tinted	NA	0.57	NA
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	NA
Nonmetal	Fixed	Tinted	0.63	0.55	NA
1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200. 2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6. 3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.	1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200. 2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6. 3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.	1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200. 2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6. 3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.	1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200. 2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6. 3.

§ 150.1 Medium relevance — show source text
Exception 2 to Section 150.1(c)3A: For each dwelling unit, up to 3 square feet of new glazing area installed in doors and up to 3 square feet of tubular skylights area with dual-pane diffusers shall not be required to meet the U -factor and SHGC requirements of Table 150.1-A. Exception 3 to Section 150.1(c)3A: In Climate Zones 2, 4, and 6 through 15, for each dwelling unit up to 16 square feet of skylight area with a maximum U -factor of 0.40 and a maximum SHGC of 0.30. In Climate Zones 1, 3, 5, and 16, there is no SHGC requirement. Exception 4 to Section 150.1(c)3A: For fenestration containing chromogenic type glazing:

i. The lower-rated labeled U -factor and SHGC shall be used with automatic controls to modulate the amount of solar gain and light transmitted into the space in multiple steps in response to daylight levels or solar intensity; ii. Chromogenic glazing shall be considered separately from other fenestration; and iii. Area-weighted averaging with other fenestration that is not chromatic shall not be permitted and shall be determined in accordance with Section 110.6(a). Exception 5 to Section 150.1(c)3A: For dwelling units containing unrated site-built fenestration that meets the maximum area restriction, the U -factor and SHGC can be determined in accordance with the Nonresidential Reference Appendix NA6 or use default values in Table 110.6-A and Table 110.6-B. B. The maximum total fenestration area shall not exceed the percentage of conditioned floor area CFA as indicated in Table 150.1-A. Total fenestration includes skylights and west-facing glazing. C. The maximum west-facing fenestration area shall not exceed the percentage of conditioned floor area as indicated in Table 150.1-A. West-facing fenestration area includes skylights tilted in any direction when the pitch is less than 1:12. 4. Shading. Where Table 150.1-A requires a maximum SHGC, the shading requirements shall be met by one of the following: A. Complying with the required maximum SHGC pursuant to Section 150.1(c)3A, or B. An exterior operable shading louver or other exterior shading device that meets the required maximum SHGC; or C. A combination of Items A and B to achieve the same performance as achieved in Section 150.1(c)3A. D. For south-facing glazing only, optimal overhangs shall be installed so that the south-facing glazing is fully shaded at solar noon on August 21 and substantially exposed to direct sunlight at solar noon on December 21. E. Exterior shading devices must be permanently secured with attachments or fasteners that are not intended for removal.

Exception to Section 150.1(c)4E: Where the California Building Code (CBC) requires emergency egress or where compliance would conflict with health and safety regulations. 5. Doors. Installed swinging door products separating conditioned space from outside or adjacent unconditioned space, but not including glazed door products, shall have an area-weighted average U-factor no greater than the applicable door value in Table 150.1-A and shall be determined in accordance with Section 110.6(a)2.
§ 0.53 Medium relevance — show source text
thermal break|Operable|Tinted|NA|0.53|NA| |Metal, thermal break|Fixed|Tinted|NA|0.57|NA| |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|NA| |Nonmetal|Fixed|Tinted|0.63|0.55|NA| |1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|

56 2025 CALIFORNIA ENERGY CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

ALL OCCUPANCIES—MANDATORY REQUIREMENTS FOR THE MANUFACTURE, CONSTRUCTION AND INSTALLATION OF SYSTEMS, EQUIPMENT AND BUILDING COMPONENTS

SECTION 110.7—MANDATORY REQUIREMENTS TO LIMIT AIR LEAKAGE

All joints, penetrations and other openings in the building envelope that are potential sources of air leakage shall be caulked, gasketed, weather-stripped or otherwise sealed to limit infiltration and exfiltration.

Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.8, and 25943, Public Resources Code.
California Energy Code Medium relevance — show source text
BTU PER HOUR**| |10
20
30
40
50|10
20
30
40
50|513
352
283
242
215|1060
727
584
500
443|2150
1480
1190
1020
901|3760
2580
2080
1780
1570|5330
3670
2940
2520
2230|11 400
7830
6290
5380
4770|20 500
14 100
11 300
9690
8590|32 300
22 200
17 900
15 300
13 500|67 400
46 300
37 200
31 800
28 200| |60
70
80
90
100|60
70
80
90
100|194
179
166
156
147|401
369
343
322
304|816
751
699
655
619|1430
1310
1220
1150
1080|2020
1860
1730
1630
1540|4320
3980
3700
3470
3280|7780
7160
6660
6250
5900|12 300
11 300
10 500
9850
9310|25 600
23 500
21 900
20 500
19 400| |125
150
175
200
250|125
150
175
200
250|131
118
109
101
90|270
244
225
209
185|549
497
457
426
377|959
869
799
744
659|1360
1230
1130
1060
935|2910
2630
2420
2250
2000|5230
4740
4360
4060
3600|8250
7470
6880
6400
5670|17 200
15 600
14 300
13 300
11 800| |300
350
400
450
500|300
350
400
450
500|81
75
70
65
62|168
155
144
135
127|342
314
292
274
259|597
549
511
480
453|847
779
725
680
643|1810
1660
1550
1450
1370|3260
3000
2790
2620
2470|5140
4730
4400
4130
3900|10 700
9840
9160
8590
8120| |550
600
650

§ 110.6 Medium relevance — show source text

(b) 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 110.6-A and SHGC values from Table 110.6-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 to Section 110.6(b): Unframed glass doors and fire doors need not be weatherstripped or caulked.

TABLE 110.6-A—DEFAULT FENESTRATION PRODUCT U-FACTORS	Col2	Col3	Col4	Col5
FRAME1,2	PRODUCT TYPE	SINGLE PANE3, 4 U-FACTOR	DOUBLE PANE1, 3, 4 U-FACTOR	GLASS BLOCK2, 3 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	NA
Metal	Glazed doors	1.25	0.77	NA
Metal	Skylight	1.98	1.3	NA
Metal, thermal break	Operable	NA	0.66	NA
Metal, thermal break	Fixed	NA	0.55	NA
Metal, thermal break	Greenhouse/garden window	NA	1.12	NA
Metal, thermal break	Glazed doors	NA	0.59	NA
Metal, thermal break	Skylight	NA	1.11	NA
Nonmetal	Operable	0.99	0.58	0.60
Nonmetal	Fixed	1.04	0.55	0.57
Nonmetal	Greenhouse/garden window	0.99	0.53	NA
Nonmetal	Glazed doors	1.94	1.06	NA
Nonmetal	Skylight	1.47	0.84	NA
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 block values when not rated by NFRC 100. 3. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6. 4. Windows with window film applied that is not rated by NFRC 100 shall use the default values from this table.	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 block values when not rated by NFRC 100. 3.

§ 205.1.1.2 Medium relevance — show source text

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.

TABLE A.5.205.1-A—DEFAULT FENESTRATION PRODUCT U-FACTORS	Col2	Col3	Col4	Col5
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.	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.	N.A. = Not applicable. 1.

§ 110.7 Medium relevance — show source text
Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|1. Translucent or transparent panels shall use glass block values when not rated by NFRC 200.
2. Visible Transmittance (VT) shall be calculated by using Reference Nonresidential Appendix NA6.
3. Windows with window film applied that is not rated by NFRC 200 shall use the default values from this table.|

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ALL OCCUPANCIES—MANDATORY REQUIREMENTS FOR THE MANUFACTURE, CONSTRUCTION AND INSTALLATION OF SYSTEMS, EQUIPMENT AND BUILDING COMPONENTS

SECTION 110.7—MANDATORY REQUIREMENTS TO LIMIT AIR LEAKAGE

All joints, penetrations and other openings in the building envelope that are potential sources of air leakage shall be caulked, gasketed, weather-stripped or otherwise sealed to limit infiltration and exfiltration.

Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.8, and 25943, Public Resources Code.

SECTION 110.8—MANDATORY REQUIREMENTS FOR INSULATION, ROOFING PRODUCTS AND RADIANT BARRIERS

(a) Insulation certification by manufacturers. All insulation shall be certified by Department of Consumer Affairs, Bureau of Household Goods 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.”

(b) Installation of urea formaldehyde foam insulation. Urea formaldehyde foam insulation may be applied or installed only if:
1. It is installed in exterior side walls; and
2. A 4-mil-thick plastic polyethylene vapor retarder or equivalent plastic sheathing vapor retarder is installed between the urea formaldehyde foam insulation and the interior space in all applications.
(c) Flamespread rating of insulation. All insulating material shall be installed in compliance with the flamespread rating and smoke density requirements of the CBC.

(d) 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 1, 2 and 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 1, 2 and 3 below.
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 meet the requirements of Section 150.0(a) for single-family buildings and Section 180.2(a)1 for multifamily buildings three habitable stories or fewer.

§ 204.4.6 Medium relevance — show source text

A6.204.4.6 Commissioning report. The CxA shall create a complete report of commissioning process activities undertaken through the design, construction and postconstruction phases of the building project and provided to the owner.

A6.204.6 Building orientation and shading. Locate orient and shade the building as required in Section A6.106.9.

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

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.

TABLE A.5.205.1-A—DEFAULT FENESTRATION PRODUCT U-FACTORS	Col2	Col3	Col4	Col5
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.

§ 180.2 Medium relevance — show source text
2(c)2, 4, 180.2(b)2A Tower 110.2(e), 120.5(a)16, 120.6(a)4, 8, 120.6(b)1, 120.6(b)5, Table 130.5B, 140.4(b)3, 140.4(h), 160.3(d)1P, 170.2(c)2C, 170.2(c)4F

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INDEX

Daylit Zone 130.1(d), 130.1(f), 140.3(c)1A, 140.6(a)2, 140.6(a)3, Table 140.6-A, 160.5(b)4D, F, 170.2(e)2B, Table 170.2-L DDC Applications and Qualifications Table 120.2-A, Table 160.3-C Dead Band 120.2(b)3, 140.4(k)7 Dead Band Flow Rate 140.4(d) Decibel Level 110.9(b)6 Decorative Gas Appliance 110.2(c), 140.6(b)4, 150.0(e), 160.1(f) Dedicated Electrical Receptacle 150.0(n)1A, 160.4 Dedicated Outdoor Air Systems (DOAS) 140.4(p), 170.2(c)4N Dedicated Raceway 150.0(s) Default Fenestration

Product U-Factors Table 110.6-A

Default Solar Heat Gain Coefficient (SHGC) Table 110.6-B, 10-111(a)1B, 110.6(a)3 Default U-Factor 10-111(a)1B, 10-111(b)1B, 10-112(a), 110.6(a)2 Default Values 10-112(a), Table 140.4-D, 150.1(c)3, 170.2(a)3A, Table 170.2-E Default Values for Fan KWdesign Based on Motor Nameplate HP Table 140.4-D, Table 170.2-E-1 Dehumidification Table 110.2-K, 120.6(h), 140.4(b)2A, 140.4(e)1, 141.1(c)1, 170.2(c)2B, 170.2(c)4C Demand Control ventilation (DCV) 120.1(d), 120.5(a)5, 160.2(c)5, 160.3(d)1 Demand-controlled local ventilation exhaust airflow rates and capture efficiency Table 150.0-E, Table 160.2-E

Demand-controlled mechanical exhaust 150.0(o), 160.2(b)2A Flexibility 150.1(b)1 Management 110.12 Recirculation 150.1(c)8, 150.2(b)1H, 170.2(d), 180.2(b)3B Response signal 110.10(b)1A, 110.10(b)1B, 110.12(a-e), 140.6(a)2, 170.2(e)2B Responsive controls 110.10(b)1A,

§ 110.6 Medium relevance — show source text

Exception 2 to Section 110.6(a)4: If the fenestration product is an alteration consisting of any area; replacement of glass in a skylight product in a building covered by the nonresidential standards, the default VT may be calculated as set forth in Reference Nonresidential Appendix NA6. 5. Labeling. Fenestration products and exterior doors shall: A. Have a temporary label for manufactured fenestration products and exterior doors or a label certificate when the component modeling approach (CMA) is used and for site-built fenestration meeting the requirements of Section 10-111(a)1. The temporary label shall not be removed before inspection by the enforcement agency; and B. Have a permanent label or label certificate when the component modeling approach (CMA) is used and for sitebuilt fenestration meeting the requirements of Section 10-111(a)2 if the product is rated using NFRC procedures. 6. Fenestration acceptance requirements. Before an occupancy permit is granted site-built fenestration products in other than single-family buildings shall be certified as meeting the Acceptance Requirements for Code Compliance, as specified in the Reference Nonresidential Appendix NA7 to ensure that site-built fenestration meets Standards requirements, including a matching label certificate for product(s) installed and be readily accessible at the project location. A certificate of accep

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ALL OCCUPANCIES—MANDATORY REQUIREMENTS FOR THE MANUFACTURE, CONSTRUCTION AND INSTALLATION OF SYSTEMS, EQUIPMENT AND BUILDING COMPONENTS

tance certifying that the fenestration product meets the acceptance requirements shall be completed, signed and submitted to the enforcement agency. Exception to Section 110.6(a): Fenestration products removed and reinstalled as part of a building alteration or addition.

Exception to Section 110.6(b): Unframed glass doors and fire doors need not be weatherstripped or caulked.

TABLE 110.6-A—DEFAULT FENESTRATION PRODUCT U-FACTORS	Col2	Col3	Col4	Col5
FRAME1,2	PRODUCT TYPE	SINGLE PANE3, 4 U-FACTOR	DOUBLE PANE1, 3, 4 U-FACTOR	GLASS BLOCK2, 3 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	NA
Metal	Glazed doors	1.25	0.77	NA
Metal	Skylight	1.98	1.3	NA
Metal, thermal break	Operable	NA	0.66	NA
Metal,

Frequently asked questions

When can I use a manufacturer NFRC label instead of defaults?

Use the manufacturer’s NFRC 100/200 label whenever it exists. The code prefers rated values; defaults only apply when an NFRC rating is not available. § 110.6 explains the preference for NFRC ratings.

If I add aftermarket film with an NFRC label, can I model the combined window+film performance?

Yes — if the film/window combination is NFRC‑rated and labeled (or the manufacturer supplies an NFRC label for the assembled product), use the rated values. If the film is not NFRC‑rated, use the table defaults.

Do I always add +0.05 for muntins or grid dividers?

Add +0.05 to the listed U‑factor for dual‑glazed products with dividers between panes if the spacer is less than 7/16 inch, and add +0.05 for any product that is a true divided lite — this is required by the table notes to Table 110.6‑A.

How do I show compliance for site‑built fenestration?

For qualifying site‑built fenestration you may calculate default values per NA6 or use the table defaults (see exceptions in § 150.1(c)3A and § 110.6 notes). You must also meet acceptance requirements before occupancy for non‑single‑family buildings.

Where is VT calculated if there is no NFRC VT label?

The code directs you to compute VT using the Reference Nonresidential Appendix NA6 when VT is not NFRC‑rated. This is in the table notes to the default tables.

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Related in the California Energy Code

How to determine fenestration U‑factor, SHGC and VT (NFRC, CMA, CMAST)

Requirements for field‑fabricated, site‑built and field‑installed fenestration

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Fenestration ratings, installation, and special glazing systems

California Energy Code