Section A4.405 — MATERIAL SOURCES

A4.405.1 Prefinished building materials. Utilize prefinished building materials which do not require additional painting or staining when possible. One or more of the following building materials that do not require additional resources for finishing are used:

1. Exterior trim not requiring paint or stain.
2. Windows not requiring paint or stain.
3. Siding or exterior wall coverings which do not require paint or stain.

A4.405.2 Concrete floors. Floors that do not require additional coverings are used including but not limited to stained, natural or stamped concrete floors.

A4.405.3 Recycled content. Comply with the requirements for recycled content in Section A4.405.3.1.

A4.405.3.1 Recycled content. Use materials, equivalent in performance to virgin materials with a total (combined) recycled content value (RCV) of:

Tier 1. The RCV shall not be less than 10 percent of the total material cost of the project.

(Equation A4. 4-1) Required Total RCV (dollars) = Total Material Cost (dollars) × 10 percent

Tier 2. The RCV shall not be less than 15 percent of the total material cost of the project.

(Equation A4. 4-2) Required Total RCV (dollars) = Total Material Cost (dollars) × 15 percent

For the purposes of this section, materials used as components of the structural frame shall not be used to calculate recycled content. The structural frame includes the load bearing structural elements, such as wall studs, plates, sills, columns, beams, girders, joists, rafters and trusses.

Notes:

1. Sample forms which allow user input and automatic calculation are located at https://www.hcd.ca.gov/building- standards/calgreen and may be used to simplify documenting compliance with this section and for calculating recycled content value of materials or assembly products.
2. Sources and recycled content of some recycled materials can be obtained from CalRecycle if not provided by the manufacturer.

A4.405.3.1.1 Total material cost. Total material cost is the total estimated or actual cost of materials and assembly products used in the project. The required total recycled content value for the project (in dollars) shall be determined by Equation A4.41 or Equation A4.4-2.

Total material cost shall be calculated by using one of the methods specified below:

1. Simplified method. To obtain the total cost of the project, multiply the square footage of the residential structure by the square foot valuation established pursuant to the ICC Building Valuation Data (BVD) or other valuation data approved and/or established by the enforcing agency. The total material cost is 45 percent of the total cost of the project. Use Equations A4.4-3A or A4.4-3B to determine total material costs using the simplified method.

(Equation A4.4-3A) Total material costs = Project square footage × square foot valuation × 45 percent

(Equation A4.4-3B) Total estimated or actual cost of project × 45 percent 2. Detailed method. To obtain the total cost of the project, add the estimated and/or actual costs of materials used for the project, including the structure (steel, concrete, wood or masonry); the enclosure (roof, windows, doors and exterior walls); the interior walls, ceilings and finishes (gypsum board, ceiling tiles, etc.). The total estimated and/or actual costs shall not include fees, labor and installation costs, overhead, appliances, equipment, furniture or furnishings.

A4.405.3.1.2 Determination of total recycled content value (RCV). Total RCV may be determined either by dollars or percentage as noted below.

1. Total recycled content value for the project (in dollars). This is the sum of the recycled content value of the materials and/or assemblies considered and shall be determined by Equation A4.4-4. The result of this calculation may be directly compared to Equations A4.4-1 and A4.4-2 to determine compliance with Tier 1 or Tier 2 prerequisites.

(Equation A4.4-4) Total Recycled Content Value (dollars) = (RCV M + RCV A ) 2. Total recycled content value for the project (by percentage). This is expressed as a percentage of the total material cost and shall be determined by Equation A4.4-4 and Equation A4.4-5. The result of this calculation may be directly compared for compliance with Tier 1 (10 percent) or Tier 2 (15 percent) prerequisites.

(Equation A4.4-5) Total Recycled Content Value (percent) = [Total Recycled Content Value (dollars) ÷ Total Material Cost (dollars)] × 100

A4.405.3.1.3 Determination of recycled content value of materials (RCV M ). The recycled content value of each material (RCV M ) is calculated by multiplying the cost of material, as defined by the recycled content. See Equations A4.4-6 and A4.4-7.

(Equation A4.4-6) RCV M (dollars) = Material cost (dollars) × RC M (percent) (Equation A4.4-7) RC M (percent) = Postconsumer content percentage + ( [1] / 2 ) Preconsumer content percentage

Notes:

1. If the postconsumer and preconsumer recycled content is provided in pounds, Equation A4.4-7 may be used, but the final result (in pounds) must be multiplied by 100 to show RC M as a percentage.

APPENDIX A4-16 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

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

APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES

2. If the manufacturer reports total recycled content of a material as one percentage in lieu of separately reporting preconsumer and postconsumer values, the total shall be considered preconsumer recycled material.

A4.405.3.1.4 Determination of recycled content value of assemblies – (RCV A ). Recycled content value of assemblies is calculated by multiplying the total cost of the assembly by the total recycled content of the assembly (RC A ), and shall be determined by Equation A4.4-8.

(Equation A4.4-8) RCV A (dollars) = Assembly cost (dollars) × Total RC A (percent) If not provided by the manufacturer, Total RC A (percent) is the sum (Σ) of the Proportional Recycled Content (PRC M ) of each material in the assembly. RC A shall be determined by Equation A4.4-9. (Equation A4.4-9) RC A = Σ PRC M

PRC M of each material may be calculated by one of two methods using the following formulas:

Method 1: Recycled content (postconsumer and preconsumer) of each material provided in percentages

(Equation A4.4-10) PRC M (percent) = Weight of material (percent) × RC M (percent)

(Equation A4.4-11) Weight of material (percent) = [Weight of material (lbs) ÷ Weight of assembly (lbs)] × 100 (See Equation A4.4-7) RC M (percent) = Postconsumer content percentage + ( [1] / 2 ) Preconsumer content percentage

Method 2: Recycled content (postconsumer and preconsumer) provided in pounds

(Equation A4.4-12) PRC M (percent) = [RC M (lbs) ÷ Weight of material (lbs)] × 100 (Equation A4.4-13) RC M (lbs) = Postconsumer content (lbs) + ( [1] / 2 ) Preconsumer content (lbs)

Note: If the manufacturer reports total recycled content of a material as one percentage in lieu of separately reporting preconsumer and postconsumer values, the total shall be considered preconsumer recycled material.

A4.405.3.1.5 Alternate method for concrete. When Supplementary Cementitious Materials (SCMs), such as fly ash or ground blast furnace slag cement, are used in concrete, an alternate method of calculating and reporting recycled content in concrete products shall be permitted. When determining the recycled content value, the percent recycled content shall be multiplied by the cost of the cementitious materials only, not the total cost of the concrete.

A4.405.4 Use of building materials from rapidly renewable sources. One or more of the following materials manufactured from rapidly renewable sources or agricultural by-products is used:

1. Insulation.

2. Bamboo or cork.

3. Engineered products.

4. Agricultural based products.

5. Other products acceptable to the enforcing agency.

Note: The intent of this section is to utilize building materials and products which are typically harvested within a 10-year or shorter cycle.