Santa Monica’s Low‑Carbon Concrete Rule, Explained
If your products touch concrete in California, Santa Monica just turned up the heat. The city now requires low‑carbon concrete in new construction, pools, and spas. That shifts submittals toward cement‑lean mixes and verifiable carbon data. Manufacturers with fast, clean EPD workflows will win specs while others play catch‑up.
What the ordinance does
Santa Monica approved a building‑code amendment in April 2024 that requires low‑carbon concrete for all new construction, swimming pools, and spas, with compliance checked at plan review. Limited exemptions cover emergencies, small on‑site batches under three cubic yards, and supply constraints. The rule took effect after second reading in mid‑May and a 30‑day window. (City of Santa Monica press release, 2024). citeturn1search5turn1search4
Why this matters to manufacturers
City staff projected the policy would cut embodied carbon from concrete used in local projects by roughly 14% to 33% without increasing typical project costs. That is a material shift in spec behavior and a clear opening for mix designs that document lower GWP. (City of Santa Monica staff report, 2024). citeturn1search3turn1search6
How “low‑carbon concrete” is shown on paper
There is no single recipe. The lever is less clinker and smarter substitutes like SCMs, backed by third‑party verified EPDs that report mix‑specific cradle‑to‑gate GWP. For projects also subject to California’s statewide code, CALGreen now provides compliance pathways that depend on transparent LCA data, including a prescriptive GWP path that compares product‑specific EPDs to threshold values. (DGS CALGreen, 2024). citeturn6search2
State backdrop that amplifies the city rule
Since July 1, 2024, CALGreen has mandatory embodied‑carbon requirements for nonresidential projects over 100,000 square feet and for school projects over 50,000 square feet, with BSC jurisdiction dropping to 50,000 square feet on January 1, 2026. Projects can comply via whole‑building LCA or via product‑specific EPD thresholds that are set as a percentage of regional averages. (DGS CALCode Quarterly Spring 2025, 2025). citeturn6search1
Translation for submittals
Expect plan check to ask for mix designs that hit performance and durability while documenting lower GWP. Product‑specific EPDs become the fastest way to prove it because they carry the verification architects, engineers, and inspectors trust. Where CALGreen applies, those EPDs line up with the prescriptive path and simplify cross‑jurisdiction reviews. (DGS CALGreen, 2024). citeturn6search2
Scope and carve‑outs to know
Santa Monica’s ordinance applies to new buildings citywide, plus pools and spas. Exemptions allow work to proceed when low‑carbon options are demonstrably unavailable or cost‑inverted for the specific pour. Small on‑site mixes under three cubic yards are excluded, which keeps homeowner‑scale jobs moving while the market scales. (City of Santa Monica press release, 2024). citeturn1search4turn1search5
Competitive playbook for producers and material suppliers
- Publish plant‑ and mix‑specific EPDs for your most requested strengths first, then round out the catalog. Aim for quick‑turn updates when SCM blends change.
- Offer submittal bundles that pair EPDs with mix performance data, curing guidance, and placement notes. Make it brain‑dead easy for project teams to check boxes.
- Benchmark your mixes to current regional GWP averages so sales can articulate percent‑better claims without over‑promising. If reliable regional numbers are missing for a strength class, say so plainly in the submittal cover.
Sales signal: this is a spec filter
When a city makes low‑carbon concrete the default, project teams penalize products that lack verified GWP. An EPD removes that friction and keeps your mix in the conversation on price, performance, and carbon rather than price alone. Missing EPDs can quietly knock you out of shortlists, and you may never hear why.
Timeline check
- April 23, 2024: Council approval for low‑carbon concrete requirement. Second reading May 14, effective 30 days later. (City of Santa Monica press release, 2024). citeturn1search4
- July 1, 2024: CALGreen embodied‑carbon rules begin for large nonresidential and school projects statewide, with thresholds expanding January 1, 2026. (DGS CALCode Quarterly Spring 2025, 2025). citeturn6search1
One last thing
Santa Monica’s building sector represents roughly a quarter of local greenhouse emissions, so the city focused on the material with the biggest early swing. Low‑carbon concrete is now table stakes. Get your data house in order, get your EPDs verified, and get your mixes ready for plan check. If that sounds like a chore, it’s because it is, but it pays off. (City of Santa Monica staff report, 2024). citeturn1search4
Frequently Asked Questions
What documentation will plan check expect under the Santa Monica low‑carbon concrete ordinance?
Expect mix designs plus third‑party verified, product‑specific EPDs that report cradle‑to‑gate GWP. Where CALGreen applies, those EPDs can be used to demonstrate compliance with prescriptive thresholds. (DGS CALGreen, 2024).
Do the CALGreen embodied‑carbon rules apply to every project in Santa Monica?
No. As of July 1, 2024, mandatory CALGreen embodied‑carbon compliance applies to nonresidential projects over 100,000 sq ft and school projects over 50,000 sq ft, with the BSC threshold dropping to 50,000 sq ft on Jan 1, 2026. Santa Monica’s ordinance applies citywide to new construction regardless of floor area. (DGS CALCode Quarterly Spring 2025, 2025).
What reduction does the city expect from the ordinance?
Staff estimated a 14% to 33% cut in embodied carbon from concrete in the building sector, without typical cost increases reported. (City of Santa Monica staff report, 2024).
About the Author
Walker Ryan is a climate-tech entrepreneur focused on driving industrial decarbonization through better data. As the founder and CEO of Parq, he helps manufacturers generate high-quality, third-party–verified carbon disclosures at scale—accelerating a traditionally slow and expensive process. Before starting Parq, Walker led over $200 million in sustainability-focused investments as VP of Strategy & Growth at ReStream Solutions, following earlier experience in investment banking at Deutsche Bank. He brings a rare mix of capital markets expertise and hands-on sustainability knowledge to tackling the infrastructure of industrial emissions.
