SECTION 150.1 – PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR NEWLY CONSTRUCTED RESIDENTIAL BUILDINGS

(a)  Basic Requirements.

New low-rise residential buildings shall meet all of the following:

1.   The requirements of Sections 110.0 through 110.10 are applicable to new residential buildings.

2.   The requirements of Section 150.0 (mandatory features).

3.   Either the performance standards or the prescriptive standards set forth in this section for the Climate Zone in which the building will be located. Climate zones are shown in Reference Joint Appendix JA2 –Weather /Climate Data.

EXCEPTION to Section 150.1(a)3: If a single contiguous subdivision or tract falls in more than one Climate Zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the Climate Zone that contains 50 percent or more of the dwelling units.

NOTE: The Commission periodically updates, publishes, and makes available to interested persons and local enforcement agencies precise descriptions of the Climate Zones, which is available in Reference Joint Appendix JA2 –Weather/Climate Data.

4.   For other provisions applicable to new low-rise residential buildings, refer to Section 100.0.

(b) Performance Standards.     

1.   Energy Budget for the Standard Design Building

The energy budget for a Standard Design Building is determined by applying the mandatory and prescriptive requirements to the Proposed Design Building.  The energy budget is the sum of the TDV energy for space conditioning, mechanical ventilation and water heating.

2.   Energy Budget for the Proposed Design Building

The energy budget for a Proposed Design Building is determined by calculating the TDV energy for the Proposed Design Building.  The energy budget is the sum of the TDV energy for space-conditioning, mechanical ventilation and water heating. The energy budget for the Proposed Design Building is reduced if on-site renewable energy generation is installed, according to methods established by the Commission in the Residential ACM Reference Manual.

3.   Calculation of Energy Budget

The TDV energy for both the Standard Design Building and the Proposed Design Building shall be computed by Compliance Software certified for this use by the Commission.  The processes for Compliance Software approval are documented in the Residential ACM Approval Manual.

4.   Compliance Demonstration Requirements for Performance Standards.

A.   Certificate of Compliance and Application for a Building Permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 which demonstrates, using an approved calculation method, that the building has been designed so that its TDV energy use from depletable energy sources does not exceed the combined water-heating and space-conditioning energy budgets for the applicable Climate Zone.

EXCEPTION to Section 150.1(b)4A: Multiple Orientation: A permit applicant may demonstrate compliance with the energy budget requirements of Section 150.1(a) and (b) For any orientation of the same building model if the documentation demonstrates that the building model with its proposed designs and features would comply in each of the four cardinal orientations.

B.   Field verification of installed features, materials, components, manufactured devices and system performance shall be documented on applicable Certificates of Installation pursuant to Section 10-103(a)3, and applicable Certificates of Verification pursuant to Section 10-103(a)5, in accordance with the following requirements when applicable:

i.    SEER Rating. When performance compliance requires installation of space a conditioning system with a SEER rating that is greater than the minimum SEER rating required by TABLE 150.1-A, the installed system shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.4.4.1.

ii.    EER Rating.  When performance compliance requires installation of a space conditioning system that meets or exceeds a specified EER rating, the installed system shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.4.4.1.

iii.   Low Leakage Air Handler.  When performance compliance requires installation of a low leakage air-handling unit that meets the qualifications in Reference Joint Appendix JA9, the installed air handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9.

(c)  Prescriptive Standards/Component Package.     

Buildings that comply with the prescriptive standards shall be designed, constructed, and equipped to meet all of the requirements for the appropriate Climate Zone shown in TABLE 150.1-A. In TABLE 150.1-A, a NA (not allowed) means that feature is not permitted in a particular Climate Zone and a NR (no requirement) means that there is no prescriptive requirement for that feature in a particular Climate Zone. Installed components shall meet the following requirements:

1.   Insulation.   

A.   Roof/Ceiling insulation shall be installed with a U-factor equal to or less than, or R-value equal to or greater than shown in TABLE 150.1-A.  The maximum U-factors or the minimum R-values shown are for insulation installed between wood-framing members.    

B.   Wall (including heated basements and crawl spaces) insulation shall be installed that has a U-factor equal to or less than, or R-value equal to or greater than shown in TABLE 150.1-A shall be installed. The maximum U-factors or minimum opaque wall R-values shown are for insulation installed between wood-framing members. Above grade mass walls and below grade walls shall have insulation installed resulting in a wall assembly U-factor equal to or less than shown in TABLE 150.1-A.

i.    Walls less than a 2x6 framed wall shall meet the equivalent U-factor indicated in TABLE 150.1-A.

ii.    Walls greater than or equal to a 2x6 framed wall shall meet the equivalent U-factor indicated in TABLE 150.1-A.

C.   Raised-floor insulation shall be installed with a U-factor equal to or less than, or an R-value equal to or greater than shown in TABLE 150.1-A. The maximum U-factors or minimum R-values shown are for insulation installed between wood-framing members.

EXCEPTION to Section 150.1(c)1C: Raised-floor insulation may be omitted if the foundation walls are insulated to meet the wall insulation minimums shown in TABLE 150.1-A, and a vapor retarder is placed over the entire floor of the crawl space, and the vents are fitted with automatically operated louvers, and the requirements of Reference Residential Appendix RA4.5.1 are met.

D.   Slab floor perimeter insulation shall be installed with a U-factor equal to or less than or R-value equal to or greater than shown in TABLE 150.1-A.  The minimum depth of concrete-slab floor perimeter insulation shall be 16 inches or the depth of the footing of the building, whichever is less.

EXCEPTION to Section 150.1(c)1: The insulation requirements of TABLE 150.1-A may also be met by ceiling, roof deck, wall, or floor assemblies that meet equivalent maximum U-factors or minimum R-values that consider the effects of all elements of the assembly, using a calculation method approved by the Executive Director.

2.   Radiant Barrier.

A radiant barrier required in TABLE 150.1-A shall meet the requirements specified in Section 110.8(j), and shall meet the installation criteria specified in the Reference Residential Appendix RA4.

3.   Fenestration.

A.   Installed fenestration products shall have an area weighted average U-factor and SHGC no greater than the applicable value in TABLE 150.1-A and shall be determined in accordance with Sections 110.6(a)2 and 110.6(a)3.

EXCEPTION 1 to Section 150.1(c)3A: For each dwelling unit, up to 3 square feet of new glazing area installed indoors and up to 3 square feet of new 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 2 to Section 150.1(c)3A: For each dwelling unit up, to 16 square feet of new skylight area with a maximum U-factor of  0.55 and a maximum SHGC of 0.30.

EXCEPTION 3 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 4 to Section 150.1(c)3A: For dwelling units containing unrated site-built fenestration only and meeting 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 Solar Heat Gain Coefficient (SHGC), the requirements shall be met by one of the following:

A.   Complying with the required SHGC pursuant to Section 150.1(c)3A; or

B.   An exterior operable shading louver or other exterior shading device that meets the required 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.   RESERVED

6.   Heating System Type.

Heating system types shall be installed as required in TABLE 150.1-A.

EXCEPTION to Section 150.1(c)6: A supplemental heating unit may be installed in a space served directly or indirectly by a primary heating system, provided that the unit thermal capacity does not exceed 2 kW or 7,000 Btu/hr and is controlled by a time-limiting device not exceeding 30 minutes.

7.   Space Heating and Space Cooling.    

All space heating and space cooling equipment shall comply with minimum Appliance Efficiency Regulations as specified in Sections 110.0 through 110.2 and meet all applicable requirements of Sections 150.0 and 150.1(c)7.

Additionally, all systems shall comply with the following requirements, as applicable:

A.   Refrigerant Charge. |t|topic=§ 150.1(c)7A - Related Topics    

When refrigerant charge verification or charge indicator display is shown as required by TABLE 150.1-A,

i     air-cooled air conditioners and air-source heat pumps (including but not limited to ducted split systems, ducted packaged systems, and mini-split systems) shall comply with the following requirements if the procedures are applicable to the system:

a.   Have measurement access holes (MAH) installed according to the specifications in the Reference Residential Appendix RA3.2.2.3 as verified by field verification and diagnostic testing; and correct refrigerant charge shall be confirmed through field verification and diagnostic testing in accordance with applicable procedures specified in Reference Residential Appendix Section RA3.2.2, or RA1; or

b.   Be equipped with a charge indicator display (CID) device that provides a clearly visible indication to the occupant when the air conditioner fails to meet the required system operating parameters specified in the applicable section of Reference Joint Appendix JA6 for the installed CID technology. The CID indication shall be constantly visible and within one foot of the air conditioner’s thermostat. CID installations shall be confirmed by field verification and diagnostic testing utilizing the procedures specified in Reference Residential Appendix RA3.4.2.

EXCEPTION to Section 150.1(c)7Aia: Systems that cannot conform to the specifications for hole location in Reference Residential Appendix Figure RA3.2-1, shall not be required to provide holes as described in Figure RA3.2-1.

EXCEPTION to Section 150.1(c)7Ai : When the outdoor temperature is less than 55 degrees F and the installer utilizes the weigh-in charging procedure in Reference Residential Appendix Section RA3.2.3.1 to verify the refrigerant charge, 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 Reference Joint Appendix JA5 and shall be capable of receiving and responding to Demand Response Signals prior to final approval of the building permit by the enforcing agency.

ii.    Air-cooled air conditioners or air-source heat pumps (including but not limited to packaged systems and mini split systems) that cannot comply with the requirements of Section 150.1(c)7Aia or 150.1(c)7Aib shall conform to the following requirement:

a.   Correct refrigerant charge shall be confirmed by the system installer utilizing the weigh-in charging procedure specified in Reference Residential Appendix RA3.2.3.1, as confirmed through field verification by a HERS Rater according to the procedure specified in Reference Residential Appendix RA3.2.3.2.

EXCEPTION to Section 150.1(c)7A: Packaged systems for which the manufacturer has verified correct system refrigerant charge prior to shipment from the factory are not required to confirm refrigerant charge through field verification and diagnostic testing. The installer of these packaged systems shall submit Certificate of Installation documentation that certifies the system is a packaged system for which the correct refrigerant charge has been verified by the system manufacturer prior to shipment from the factory.

8.   Domestic Water-Heating Systems.      

Water-heating systems shall meet the requirements of either A, B C, or D.

A.   For systems serving individual dwelling units, a single gas or propane storage type water heater with an input of 75,000 Btu per hour or less, and that meets the tank insulation requirements of Section 150.0(j) and the requirements of Sections 110.1 and 110.3 shall be installed. For recirculation distribution systems, only Demand Recirculation Systems with manual control pumps shall be used.

B.   For systems serving individual dwelling units, a single gas or propane instantaneous water heater with an input of 200,000 Btu per hour or less and no storage tank, and that meets the requirements of Sections 110.1 and 110.3 shall be installed. For recirculation distribution systems, only Demand Recirculation Systems with manual control pumps shall be used.

C.   For systems serving multiple dwelling units, a central water-heating system that includes the following components shall be installed:

i.    Gas or propane water heaters, boilers or other water heating equipment that meet the minimum efficiency requirements of Sections 110.1 and 110.3; and

ii.    A water heating recirculation loop that meets the requirements of Sections 110.3(c)2 and 110.3(c)5 and is equipped with an automatic control system that controls the recirculation pump operation based on measurement of hot water demand and hot water return temperature and has two recirculation loops each serving half of the building; and

EXCEPTION to Section 150.1(c)8Cii: Buildings with eight or fewer dwelling units are exempt from the requirement for two recirculation loops.

iii.   A solar water-heating system meeting the installation criteria specified in Reference Residential Appendix RA4 and with a minimum solar savings fraction of 0.20 in Climate Zones 1 through 9 or a minimum solar savings fraction of 0.35 in Climate Zones 10 through 16. The solar savings fraction shall be determined using a calculation method approved by the Commission.

D.   For systems serving individual dwelling units, an electric-resistance storage or instantaneous water heater may be installed as the main water heating source only if natural gas is unavailable, the water heater is located within the building envelope, and a solar water-heating system meeting the installation criteria specified in the Reference Residential Appendix RA4 and with a minimum solar savings fraction of 0.50 is installed. The solar savings fraction shall be determined using a calculation method approved by the Commission.  Recirculation pumps shall not be used.

9.   Space conditioning ducts.     

All ducts shall either be in directly conditioned space as confirmed by field verification and diagnostic testing in accordance with Reference Residential Appendix RA3.1.4.3.8 or be insulated to a minimum installed level as specified by TABLE 150.1-A. All ducts shall meet all applicable mandatory requirements of Section 150.0(m).

NOTE: Requirements for duct insulation in TABLE 150.1-A do not apply to buildings with space conditioning systems that do not have ducts. 

10.  Central Fan Integrated Ventilation Systems.

Central forced air system fans used in central fan integrated ventilation systems shall demonstrate, in Air Distribution Mode, an air-handling unit fan efficacy less than or equal to 0.58 W/CFM as confirmed through field verification and diagnostic testing in accordance with all applicable procedures specified in Reference Residential Appendix RA3.3.

11.  Roofing products.

All roofing products shall meet the requirements of Section 110.8 and the applicable requirements of Subsection A or B:

A.   Low-rise residential buildings with steep-sloped roofs, in Climate Zones 10 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.

B.   Low-rise residential buildings with low-sloped roofs; in Climate Zones 13 and 15 shall have a minimum aged solar reflectance of 0.63 and a minimum thermal emittance of 0.75 or a minimum SRI of 75.

EXCEPTION 1 to Section 150.1(c)11: Building integrated photovoltaic panels and building integrated solar thermal panels are exempt from the minimum requirements for solar reflectance and thermal emittance or SRI.

EXCEPTION 2 to Section 150.1(c)11: Roof constructions that have thermal mass over the roof membrane with a weight of at least 25 lb/ft² are exempt from the minimum requirements for solar reflectance and thermal emittance or SRI.

12.  Ventilation Cooling.     

Single family homes shall comply with the Whole House Fan (WHF) requirements shown in TABLE 150.1-A. When a WHF is required, comply with Subsections A through C below:

A.   Have installed one or more WHFs whose total Air Flow CFM as 'listed in the CEC Directory is at least 2 CFM/ft2 of conditioned floor area; and

B.   Have at least 1 square foot of attic vent free area for each 375 CFM of rated whole house fan Air Flow CFM; and

C.   Provide homeowners who have WHFs with a one page “How to operate your whole house fan” informational sheet.

13.  HVAC System Bypass Ducts.

Unless otherwise specified on the Certificate of Compliance, bypass ducts that deliver conditioned supply air directly to the space conditioning system return duct airflow shall not be used. All zonally controlled forced air systems shall be verified by a HERS Rater utilizing the procedure in Reference Residential Appendix Section RA3.1.4.6 to confirm compliance with 150.1(c)13.

 

TABLE 150.1-A  COMPONENT PACKAGE-A   Standard Building Design

 

Climate Zone

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Building Envelope

 

Insulation1

 

Roofs /Ceilings

 

U 0.025

R 38

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031

R 30

U 0.031 R 30

U 0.025 R 38

U 0.025 R 38

U 0.025

R 38

U 0.025

R 38

U 0.025

R 38

U 0.025

R 38

Walls

 

Above Grade

2x4

Framed2

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065 R15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

U 0.065

R 15+4

or

R 13+5

Mass Wall Interior3

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U  0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.059

R 17

Mass Wall Exterior3

U 0.125

R 8.0

U 0.125

R 8.

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.125

R 8.0

U 0.1025

R 8.0

U 0.125

R 8.0

U 0.070

R 13

Below Grade

Below Grade Interior3

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.070

R 13

U 0.066

R 15

Below Grade Exterior3

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.200

R 5.0

U 0.100

R 10

U 0.100

R 10

U 0.053

R 19

Floors

Slab Perimeter

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

U 0.58

R 7.0

Raised

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

U 0.037

R 19

Concrete Raised

U 0.092

R 8.0

U 0.092

R 8.0

U 0.269

R 0

U 0.269

R 0

U0.269

R 0

U 0.269

R 0

U 0.269

R 0

U 0.269

R 0

U 0.269

R 0

U 0.269

R 0

U 0.092

R 8.0

U 0.138

 R  4.0

U 0.092

R 8.0

U 0.092

R 8.0

U 0.138

R 4.0

U 0.092

R 8.0

Radiant Barrier

 

NR

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

NR

Roofing Products

Low-sloped

 

Aged Solar Reflectance

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

0.63

NR

0.63

NR

Thermal Emittance

 

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

NR

0.75

NR

0.75

NR

 

Steep-sloped

 

Aged Solar Reflectance

NR

NR

NR

NR

NR

NR

NR

NR

NR

0.20

0.20

0.20

0.20

0.20

0.20

NR

Thermal Emittance

NR

NR

NR

NR

NR

NR

NR

NR

NR

0. 75

0.75

0.75

0.75

0.75

0.75

NR

Fenestration

 

Maximum U-factor4

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

0.32

Maximum SHGC5

NR

0.25

NR

0.25

NR

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

Maximum Total Area

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

20%

Maximum West Facing Area

NR

5%

NR

5%

NR

5%

5%

5%

5%

5%

5%

5%

5%

5%

5%

5%

 

CONTINUED: TABLE 150.1-A  COMPONENT PACKAGE-A   Standard Building Design

 

Climate Zone

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

HVAC SYSTEM

 

Space Heating8

Electric-Resistance Allowed

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

If gas, AFUE

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

If Heat Pump, HSPF6

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

Space
 cooling

SEER

 

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

MIN

Refrigerant Charge Verification or Charge Indicator Display

NR

REQ

NR

NR

NR

NR

NR

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

NR

Whole House Fan7

NR

NR

NR

NR

NR

NR

NR

REQ

REQ

REQ

REQ

REQ

REQ

REQ

NR

NR

Central System Air Handlers

Central Fan Integrated Ventilation System Fan Efficacy

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

REQ

Ducts

Duct Insulation

R-6

R-6

R-6

R-6

R-6

R-6

R-6

R-6

R-6

R-6

R-8

R-6

R-6

R-8

R-8

R-8

Water Heating

All Buildings

System Shall meet Section 150.1(c)8

 

Footnote requirements to TABLE 150.1-A:

1.   The U-factors/R-values shown for ceiling, wall and raised floor insulation are for wood-frame construction with insulation installed between the framing members.  For alternative construction assemblies, see Section 150.1(c)1A, B and C.

2.   U-factors can be met by cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that results in a U-factor equal to or less than the U-factor shown.  “R-15+4” means R-15 cavity insulation plus R-4 continuous insulation sheathing.  Any combination of cavity insulation and/or continuous insulation that results in a U-factor equal to or less than 0.065 is allowed, such as R-13+5.  

3.   Mass wall has a thermal heat capacity greater than or equal to 7.0 Btu/h-ft2.  Below grade “interior” denotes insulation installed on the inside surface of the wall.  Below grade “exterior” denotes insulation installed on the outside surface of the wall.

4.   The installed fenestration products shall meet the requirements of Section 150.1(c)3.

5.   The installed fenestration products shall meet the requirements of Section 150.1(c)4.

6.   HSPF means "heating seasonal performance factor."

7.   When whole house fans are required (REQ), only those whole house fans that are 'listed in the Appliance Efficiency Directory may be installed. Compliance requires installation of one or more WHFs whose total airflow CFM is capable of meeting or exceeding a minimum 2 cfm/square foot of conditioned floor area per Section 150.1(c)12.

8.   A supplemental heating unit may be installed in a space served directly or indirectly by a primary heating system, provided that the unit thermal capacity does not exceed 2 kilowatts or 7,000 Btu/hr and is controlled by a time-limiting device not exceeding 30 minutes.