EXCEPTION 1 to Section 150.2(a): Additions of 300 square feet or less are exempt from the roofing requirements of Section 150.1(c)11.
EXCEPTION 2 to Section 150.2(a): Existing inaccessible piping shall not require insulation as defined under Section 150.0(j)1.
EXCEPTION 3 to Section 150.2(a): Space-Conditioning System. When heating or cooling will be extended to an addition from the existing system(s), the existing heating and cooling equipment need not comply with Part 6. The heating system capacity must be adequate to meet the minimum requirements of CBC Section 1204.1.
EXCEPTION 4 to Section 150.2(a): Space-Conditioning System Ducts. When any length of duct is extended from an existing duct system to serve the addition, the existing duct system and the extended duct shall meet the applicable requirements specified in Section 150.2(b)1Di and 150.2(b)1Dii.
EXCEPTION 5 to Section 150.2(a): Additions 1,000 square feet or less are exempt from the Ventilation Cooling requirements of Section 150.1(c)12.
EXCEPTION 6 to Section 150.2(a): Photovoltaic systems, as specified in Section 150.1(c)14, are not required for additions.
EXCEPTION 7 to Section 150.2(a): Space Heating System. New or replacement space heating systems serving an addition may be a heat pump or gas heating system.
EXCEPTION to Section 150.2(a)1B: Insulation in an enclosed rafter ceiling shall meet the requirements of Section 150.0.
EXCEPTION 1 to Section 150.2(b)1A: Alterations that add fenestration area of up to 75 square feet shall not be required to meet the total fenestration area and west-facing fenestration area requirements of Sections 150.1(c)3B and C.
EXCEPTION 2 to Section 150.2(b)1A: Alterations that add up to 16 square feet of new skylight area with a maximum U-factor of 0.55 and a maximum SHGC of 0.30 area shall not be required to meet the total fenestration area and west-facing fenestration area requirements of Sections 150.1(c)3B and C.
EXCEPTION 1 to Section 150.2(b)1B: Replacement of vertical fenestration no greater than 75 square feet with a U-factor no greater than 0.40 in Climate Zones 1-16, and a SHGC value no greater than 0.35 in Climate Zones 2, 4, and 6-15.
EXCEPTION 2 to Section 150.2(b)1B: Replaced skylights must meet a U-factor no greater than 0.55, and a SHGC value no greater than 0.30.
NOTE: Glass replaced in an existing sash and frame or sashes replaced in an existing frame are considered repairs, provided that the replacement is at least equivalent to the original in performance.
Climate Zone | 3, 5 through 7 | 1, 2, 4, 8 through 16 |
Duct R-Value | R-6 | R-8 |
Entirely new or complete replacement duct systems installed as part of an alteration is constructed of at least 75 percent new duct material, and up to 25 percent may consist of reused parts from the dwelling unit's existing duct system, including but not limited to registers, grilles, boots, air handler, coil, plenums, duct material; if the reused parts are accessible and can be sealed to prevent leakage.
Entirely new or complete replacement duct systems shall also conform to the requirements of Sections 150.0(m)12 and 150.0(m)13. If the air handler and ducts are located within a vented attic, the requirements of Section 150.2(b)1J shall also be met.
EXCEPTION to Section 150.2(b)1Diib: Duct Sealing. Existing duct systems that are extended, which are constructed, insulated or sealed with asbestos.
EXCEPTION 1 to Section 150.2(b)1E: Duct sealing. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in the Reference Residential Appendix RA3.1.
EXCEPTION 2 to Section 150.2(b)1E: Duct sealing. Duct systems with less than 40 linear feet as determined by visual inspection.
EXCEPTION 3 to Section 150.2(b)1E: Duct sealing. Existing duct systems constructed, insulated or sealed with asbestos.
EXCEPTION to Section 150.2(b)1Fii: Entirely new or complete replacement packaged systems for which the manufacturer has verified correct system refrigerant charge prior to shipment from the factory are not required to have refrigerant charge confirmed through field verification and diagnostic testing. The installer of these packaged systems shall certify on the Certificate of Installation that the packaged system was pre-charged at the factory and has not been altered in a way that would affect the charge. Ducted systems shall comply with minimum system airflow rate requirement in Section 150.2(b)1Fiia, provided that the system is of a type that can be verified using the procedure specified in RA3.3 or an approved alternative in RA1.
EXCEPTION 1 to Section 150.2(b)1Fiia: Systems unable to comply with the minimum airflow rate requirement shall demonstrate compliance using the procedures in Section RA3.3.3.1.5; and the system's thermostat shall conform to the specifications in Section 110.12.
EXCEPTION 2 to Section 150.2(b)1Fiia: Entirely new or complete replacement space conditioning systems, as specified by section 150.2(b)1C, without zoning dampers may comply with the minimum airflow rate by meeting the applicable requirements in Tables- 150.0-B or 150.0-C as confirmed by field verification and diagnostic testing in accordance with the procedures in Reference Residential Appendix Section RA3.1.4.4 and RA3.1.4.5. The design clean-filter pressure drop requirements of Section 150.0(m)12C for the system air filter device(s) shall conform to the requirements given in Tables 150.0-B and 150.0-C.
EXCEPTION 1 to Section 150.2(b)1Fiib: When the outdoor temperature is less than 55°F and the installer utilizes the weigh-in charging procedure in Reference Residential Appendix Section RA3.2.3.1 to demonstrate compliance, the installer may elect to utilize the HERS Rater verification procedure in Reference Residential Appendix Section RA3.2.3.2. If the HERS Rater verification procedure in Section RA3.2.3.2 is used for compliance, the system's thermostat shall conform to the specifications in Section 110.12. Ducted systems shall comply with the minimum system airflow rate requirements in Section 150.2(b)1Fiia.
EXCEPTION to Section 150.2(b)1Fiii: Entirely new or complete replacement packaged systems for which the manufacturer has verified correct system refrigerant charge prior to shipment from the factory are not required to have refrigerant charge confirmed through field verification and diagnostic testing. The installer of these packaged systems shall certify on the Certificate of Installation that the packaged system was pre-charged at the factory and has not been altered in a way that would affect the charge. Ducted systems shall comply with minimum system airflow rate requirement in Section 150.2(b)1Fiiib, provided that the system is of a type that can be verified using the procedure specified in Section RA3.3 or an approved alternative in Section RA1.
EXCEPTION 1 to Section 150.2(b)1G: Non-ducted electric resistance space heating systems, if the existing space heating system is electric resistance.
EXCEPTION 2 to Section 150.2(b)1G: Ducted electric resistance space heating systems, if the existing space heating system is electric resistance and a ducted space cooling system is not being replaced or installed.
EXCEPTION 3 to Section 150.2(b)1G: Electric resistance space heating systems, if the existing space heating system is electric resistance and the building is located in Climate Zones 7 or 15.
New roofing products in Climate Zones 4 and 8 through 15 shall have a minimum aged solar reflectance of 0.20 and a minimum thermal emittance of 0.75, or a minimum SRI of 16.
EXCEPTION 1 to Section 150.2(b)1Ii: The following shall be considered equivalent to Subsection i:
EXCEPTION 2 to Section 150.2(b)1Ii: Roof area covered by building integrated photovoltaic panels or building integrated solar thermal panels is not required to meet minimum requirements for aged solar reflectance, thermal emittance, or SRI.
EXCEPTION 3 to Section 150.2(b)1Ii: Roof constructions with a weight of at least 25 lb/ft2 are exempt from minimum requirements for aged solar reflectance and thermal emittance, or SRI.
EXCEPTION 1 to Section 150.2(b)1Iiia: The aged solar reflectance can be met by using insulation at the roof deck specified in TABLE 150.2-B.
Minimum Aged Solar Reflectance
|
Roof Deck Continuous Insulation R-Value (Climate Zones 6-7)
|
Roof Deck Continuous Insulation R-value (Climate Zones 2, 4, & 8-15)
|
0.60
|
2
|
16
|
0.55
|
4
|
18
|
0.50
|
6
|
20
|
0.45
|
8
|
22
|
No Requirement
|
10
|
24
|
EXCEPTION 2 to Section 150.2(b)1Iiia: Roof area covered by building integrated photovoltaic panels or building integrated solar thermal panels are not required to meet the minimum requirements for aged solar reflectance, thermal emittance, or SRI.
EXCEPTION 3 to Section 150.2(b)1Iiia: Roof constructions with a weight of at least 25 lb/ft2 are exempt from the minimum requirements for aged solar reflectance and thermal emittance, or SRI.
Climate Zone | Continuous Insulation R-value | Roof Assembly U-factor |
3, 5-7 | NR | NR |
1, 2, 4, 8-16 | R-14 | 0.039 |
EXCEPTION 1 to Section 150.2(b)1Iiib: Existing roofs with R-10 or greater continuous insulation above or below the roof deck; or
EXCEPTION 2 to Section 150.2(b)1Iiib: Existing roofs with an assembly U-factor of 0.056 or less or that are insulated with at least R-19 insulation between the roof rafters and in contact with the roof deck in Climate Zones 1, 2, 4, and 8 through 10; or
EXCEPTION 3 to Section 150.2(b)1Iiib: The continuous insulation requirements of Table 150.2-C may be reduced to R-4 where the following conditions are met:
- Mechanical equipment is located on the roof and will not be temporarily disconnected and lifted as part of the roof replacement and the addition of insulation required by Table 150.2-C would reduce the height from the roof surface to the top of the base flashing to less than that set forth in the manufacturer’s installation instructions as per California Residential Code Section R900; or
- Replaced roofing abuts sidewall or parapet walls and the addition of insulation required by Table 150.2-C would reduce the height from the roof surface to the top of the base flashing to less than that set forth in the manufacturer’s installation instructions as per California Residential Code Section R900, provided that the following conditions apply:
- The sidewall or parapet walls are finished with an exterior cladding material other than the roof covering membrane material; and
- The sidewall or parapet walls have exterior cladding material that must be removed to install the new roof covering membrane to maintain the minimum base flashing height; and
- The ratio of the replaced roof area to the linear dimension of affected sidewall or parapet walls is less than 25 square feet per linear foot; or
EXCEPTION 4 to Section 150.2(b)1Iiib: The continuous insulation requirements per Table 150.2-C may be reduced where increasing the thickness of above deck insulation would reduce the flashing around an existing exterior wall opening below what is permitted by the fenestration or door manufacturer’s installation instructions, or registered design professionals approved flashing design, as per the California Residential Code Section R703.4, or by California Residential Code Section R905.2.8.3.
EXCEPTION 5 to Section 150.2(b)1Biib: Tapered insulation with thermal resistance less than prescribed at the drains and other low points may be used provided that the thickness of insulation is increased at the high points of the roof so that the average thermal resistance equals or exceeds the required value.
EXCEPTION to Section 150.2(b)1Ji: In Climate Zones 1, 3, and 6, dwelling units with at least R-19 existing insulation installed at the ceiling level.
EXCEPTION 1 to Section 150.2(b)1Jii: Dwelling units with at least R-19 existing insulation installed at the ceiling level.
EXCEPTION 2 to Section 150.2(b)1Jii: Dwelling units with atmospherically vented space heating or water heating combustion appliances located inside the pressure boundary of the dwelling unit.
EXCEPTION 1 to Section 150.2(b)1Jiii: In Climate Zones 1 through 4 and 8 through 10, dwelling units with at least R-19 existing insulation installed at the ceiling level.
EXCEPTION 1 to Section 150.2(b)1J: Dwelling units with at least R-38 existing insulation installed at the ceiling level.
EXCEPTION 2 to Section 150.2(b)1J: Dwelling units where the alteration would directly cause the disturbance of asbestos.
EXCEPTION 3 to Section 150.2(b)1J: Dwelling units with knob and tube wiring located in the vented attic.
EXCEPTION 4 to Section 150.2(b)1J: 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 806.3 of Title 24, Part 2.5.
EXCEPTION 5 to Section 150.2(b)1J: Where the attic space above the altered dwelling unit is shared with other dwelling units and the requirements of Section 150.2(b)1J are not triggered for the other dwelling units.
The altered component(s) and any newly installed equipment serving the alteration shall meet the applicable requirements of subsections A, B, and C below.
Altered Component | Standard Design Without Third Party Verification of Existing Conditions Shall be Based On | Standard Design With Third Party Verification of Existing Conditions Shall be Based On |
Ceiling Insulation, Wall Insulation, and Raised-floor Insulation | The existing insulation R-value | |
Fenestration | The U-factor of 0.40 and SHGC value of 0.35. The glass area shall be the glass area of the existing building. | If the proposed U-factor is ≤ 0.40 and SHGC value is ≤ 0.35, the standard design shall be based on the existing U-factor and SHGC values as verified. Otherwise, the standard design shall be based on the U-factor of 0.40 and SHGC value of 0.35. The glass area shall be the glass area of the existing building. |
Window Film | The U-factor of 0.40 and SHGC value of 0.35. | The existing fenestration in the alteration shall be based on TABLE 110.6-A and TABLE 110.6-B. |
Doors | The U-factor of 0.20. The door area shall be the door area of the existing building. | If the proposed U-factor is < 0.20, the standard design shall be based on the existing U-factor value as verified. Otherwise, the standard design shall be based on the U-factor of 0.20. The door area shall be the door area of the existing building. |
Space-Heating and Space-Cooling Equipment | Table 150.1-A for equipment efficiency requirements; Section 150.2(b)1C for entirely new or complete replacement systems; Section 150.2(b)1F for refrigerant charge verification requirements. | The existing efficiency levels. |
Air Distribution System – Duct Sealing | The requirements of Sections 150.2(b)1D and 150.2(b)1E | The requirements of Sections 150.2(b)1D and 150.2(b)1E |
Air Distribution System – Duct Insulation | The proposed efficiency levels. | The existing efficiency levels. |
Water Heating Systems | The requirements of Section 150.2(b)1Hii | The existing efficiency level. |
Roofing Products | The requirements of Section 150.2(b)1I. | The requirements of Section 150.2(b)1I |
All Other Measures | The proposed efficiency levels. | The existing efficiency levels. |
NOTES TO SECTION 150.2(b)2:
EXCEPTION 1 to Section 150.2(b): Any dual-glazed greenhouse or garden window installed as part of an alteration complies with the U-factor requirements in Section 150.1(c)3.
EXCEPTION 2 to Section 150.2(b): Where the space in the attic or rafter area is not large enough to accommodate the required R-value, the entire space shall be filled with insulation provided such installation does not violate Section 1203.2 of Title 24, Part 2.
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, 25402.5, 25402.8, 25910, and 25943, Public Resources Code.