Did you hear the news? California has updated the Green Building Code with additional embodied carbon requirements, making building codes even more complicated and likely to impact your next new build.
These requirements went into effect July 1, 2024. Refer to the information below for a requirement breakdown.
What is Embodied Carbon?
CALGreen Title 24, Part 11 made some serious changes to embodied carbon reduction requirements. You might have found yourself deep in the weeds of carbon emissions, questioning whether or not you need to onboard a chemist to stay up to code. Embodied carbon is the greenhouse gas (GHG) emissions produced by building materials from top to bottom of the supply chain. This includes raw material extraction, manufacturing, transportation, installation, maintenance, and disposal of your building materials. This does not include operational carbon (day-to-day building operations). See one of Green Badger’s recent blog posts The Basics of Embodied Carbon for more information.
Required Projects
Commercial and non-residential buildings 100,000 square feet or larger are required to comply with CALGreen Title 24, Part 11, Embodied Carbon Reduction. CALGreen Title 24, Part 11, requires school buildings of 50,000 square feet or larger to comply with Embodied Carbon Reduction standards.
Pathways to Compliance
Building Reuse (Section 5.105)
- Required: Reuse 45% of an existing building structure and enclosure
- Tier 1: Reuse 75% of an existing structure and enclosure
- Tier 2: Reuse 75% of an existing building and enclosure AND reuse 30% of interior non-structural elements
- Building Elements Defined: Existing structural elements: beams, columns, walls, foundations, floors, and lateral elements
- Existing enclosure elements: wall framing, exterior finishes, roof framing
- Excluded elements: window assemblies, insulation, structural failures
Performance: Whole Building Life-Cycle Assessment (WB LCA) (Section 5.409)
- Required: Conduct a whole building life-cycle assessment resulting in 10% reduction from baseline
- Tier 1: Conduct a whole building life-cycle assessment resulting in 15% reduction from baseline
- Tier 2: Conduct a whole building life-cycle assessment resulting in 20% reduction from baseline, including a GWP analysis
- WB LCA Defined:
- For new buildings, conduct a 60-year cradle-to-grave whole building life-cycle assessment demonstrating at minimum 10% reduction in global warming potential (GWP).
- Components: Structural members, glazing, insulation, exterior finishes
- Excludes: Operational energy
Prescriptive: Environmental Product Declarations (EPDs) (Section 5.409.3)
- Required: Use materials with industry wide EPDs at 175% of industry average global warming potential limits
- Tier 1: Use materials with industry wide EPDs at 150% of industry average global warming potential limits
- Tier 2: Use materials with industry wide EPDs for at 130% of industry average global warming potential limits
- Material EPDs Defined:
- Components: Structural steel, rebar, flat glass, light and heavy duty mineral wool insulation, and ready-mix concrete. See link above for GWP limits.
- Concrete mixes can use a weighted average for all mixes (130% of ready-mixed GWP values)
Let’s assume the prescriptive path of EPDs is the easiest route to take for compliance. Typically an EPD will contain the total GWP for the materials in your building. You can also refer to the EC3 calculator to obtain the magic GWP number. The challenge can be understanding unfamiliar software with incredibly unfamiliar requirements.
Green Badger has a helpful blog post Uncovering Embodied Carbon in EPDs that provides a guide on deciphering GWP totals. Green Badger also provides a software system with an extensive database containing hundreds of EPDs to help you comply with CALGreen Title 24, Part 11 – Embodied Carbon Reduction Requirements.
