CALGreen is California's green building code (Title 24, Part 11) — the first state-mandated green building code in the United States. Officially known as the California Green Building Standards Code, it applies to the planning, design, operation, construction, use, and occupancy of all newly constructed or significantly renovated buildings or structures statewide. Title 24, Part 11, specifically addresses embodied carbon in buildings, effective as of July 1, 2024.
CALGreen's mandate spans five areas:
1. Planning and design Site development
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2. Energy efficiency Compliance with Title 24, Part 6, of the California Energy Code
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3. Water efficiency and conservation Indoor water use
Outdoor water use
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4. Material conservation and resource efficiency Building material
Construction waste reduction
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5. Environmental quality Indoor air quality
Pollutant control
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Title 24, Part 11 covers new residential and non-residential buildings, and significant additions and alterations. It applies to:
CALGreen includes both mandatory measures and voluntary tiers (Tier 1 and Tier 2). These tiers encourage higher sustainability:
Starting July 1, 2024, CALGreen requires non-residential building projects exceeding 100,000 sf and school projects exceeding 50,000 sf to address the climate impact of building materials. This is the first statewide embodied carbon building code in the US. Building materials account for 11% of greenhouse gasses (GHG) worldwide. The focus has now shifted to delivering lower embodied carbon projects.
The buildings outlined above must meet one of three compliance pathways for embodied carbon:
The global buildings sector continues to grow, with global floor area expected to double by 2060. New buildings contribute to 11% of worldwide GHG, so building reuse is extremely beneficial.
Requirements for building reuse: Maintain a minimum of 45% combined of the existing building's primary structural elements (foundations, columns, beams, walls, floors, lateral elements) and enclosure (roof framing, wall framing, exterior finishes). The calculation does not include window assemblies, insulation, and portions of buildings deemed structurally unsound or hazardous.
Conduct a 60-year cradle-to-grave whole building LCA (excluding operating energy), with the following results:
WBLCA evaluates the environmental impacts of a building throughout its entire life-cycle. The steps include:
How to calculate a baseline for your project
Easily create reference buildings using One Click LCA’s early design tool, Carbon Designer 3D. Create and design options with just building size and type, calculate baseline carbon emissions, and quickly find ways to reduce emissions.
To achieve this pathway, you'll need to prove compliance through environmental product declarations (EPDs). EPDs quantify the environmental impact of materials throughout their life-cycle. According to CALGreen, you will need to provide EPDs for the following materials on your building project: steel, glass, mineral wool, concrete, with lower than specified GWP.
The specified limit is 175% of the industry average GWP for that material. The standard for CALGreen is the same as the Buy Clean California Act, with the addition of ready-mixed concrete.
In the U.S., there are two widely known and commonly used types of EPDs: Industry average and product-specific. Industry average EPDs are developed by organizations (e.g. National Ready Mixed Concrete Association). Data is collected from various constituents and the average data is shared through an EPD. Manufacturers publish product-specific EPDs for their specific products. To fulfill this pathway of CALGreen you will need to provide product-specific EPDs.
Steps for submitting EPDs:
One Click LCA is an all-inclusive source for CALGreen’s EPD requirements which include:
Incentives for achieving Tiers 1 and 2 depend on the jurisdiction and specific programs available. Some general incentives include:
One Click LCA's CALGreen-specific tool is designed to help projects comply with Title 24, Part 11 regulations. This tool simplifies compliance by:
It features the world's largest database of material EPDs and can generate comparative LCA documents to align with CALGreen and LEED requirements.
Title 24's embodied carbon regulations took effect on July 1, 2024. California is raising the bar for embodied carbon reduction in the building sector. These new standards require developers to follow one of three compliance pathways: Building reuse, whole building life-cycle assessment (WBLCA), or environmental product declarations (EPDs).
One Click LCA's CALGreen tool simplifies the process by integrating with Revit, other BIM, and energy models, automating embodied carbon calculations, and streamlining documentation and reporting. By utilizing this tool, architects and builders can easily meet the new standards, reducing the environmental impact of their construction projects and supporting California's climate goals.