City Council
Report
City Council Meeting: April 23, 2024
Agenda Item: 10.A
1 of 13
To: Mayor and City Council
From: Rick Valte, Public Works Director, Public Works, Office of Sustainability & the Environment
Subject: Introduction and First Reading of Low-Carbon Concrete Policy Ordinance and Adoption of Local Amendments Findings Resolution
Recommended Action
Staff recommends that the City Council:
1. Adopt a finding of categorical exemption pursuant to Section 15308 of the California Environmental Quality Act (CEQA) Guidelines;
2. Introduce for first reading the attached ordinance that adopts the 2022 California Green Building Standards Code including the 2022 intervening code updates, and supports decreasing emissions from concrete;
3. Adopt the attached resolution that provides findings of local climatic, geological, topographical, and environmental conditions as required to adopt Santa Monica local amendments to the 2022 California Green Building Standards Code;
4. Direct the City Manager to file the adopted resolution and ordinance amending the Green Building Standards Code with the California Building Standards Commission following the second reading of the ordinance.
Summary
As a leader in sustainability, the City of Santa Monica continues to implement strategies that support its goals for a clean, safe, healthy, and sustainable community. As adopted by the City Council, the Climate Action and Adaptation Plan (Attachment A) recommends implementing carbon-neutral construction codes for new residential, commercial, and multi-family properties. Embodied carbon, the carbon emissions from the manufacturing and transportation of building materials, accounts for 11% of global carbon emissions and contributes up to a quarter of building sector emissions. Locally, the proposed low-carbon concrete amendment to the Building Code could reduce the City’s building sector concrete embodied carbon by 14%-33%. 2 of 13
New construction buildings offer a major opportunity to mitigate future emissions given the long-term nature of a building as an asset. Low-carbon concrete requirements provide an opportunity to drastically reduce future carbon emissions. A typical concrete mix is made of Portland cement (cement), water, sand, and aggregates (gravel). The process of creating cement is carbon-intensive and accounts for 60% of the emissions in concrete1. Low-carbon concrete produces lower emissions compared to conventional concrete mixes by reducing the amount of cement in the concrete mix and replacing that cement with alternative cementitious materials and does so at lower to the same cost as traditional concrete. Because of the opportunity to reduce carbon emissions while not impacting overall building costs, there is growing momentum to establish lowcarbon concrete requirements as the most viable path to reduce embodied carbon in new construction. Policies reducing embodied carbon in the building sector are taking effect at the federal, state, and municipal government levels with many targeting lowcarbon concrete.
Staff proposes that City Council adopt and amend a measure in the California Green Building Standards Code (CALGreen) to reduce embodied carbon emissions from concrete by establishing cement and global warming potential limits for concrete used in Santa Monica. This amendment would build upon the community’s adopted goal of reducing carbon emissions from the building sector, which accounts for 26% of greenhouse gas emissions in Santa Monica. Moreover, adopting the local amendment would close the gap in reducing building sector emissions as the Climate Action and Adaptation Plan sets goals for operational emissions and does not account for embodied carbon emissions. If adopted, staff would continue to conduct extensive outreach to the building community to prepare stakeholders for the ordinance’s effective date.
Formal adoption of the 2022 CALGreen Code and deletion of the following prior code sections comes at the behest of Building & Safety: 8.106.050 Additional Definitions, 1 Miller, “Achieving net zero greenhouse gas emissions in the cement industry via value chain mitigation strategies”, 2021.
3 of 13
8.106.053 Green building, 8.106.070 Flashing details, and 8.106.080 Non-residential, high-rise residential, hotel and motel solar and pool heating requirements. Sections
8.106.010 Adoption, 8.106.020 Local amendments to the California Green Building Standards Code, and 8.106.100 Electric vehicle charging have been updated to reflect current code cycles. (These are code cleanup measures.) Background
Limiting global warming to under 1.5 degrees Celsius above pre-industrial levels is imperative for avoiding the disastrous and irreparable effects of climate change. To meet this goal, action must be taken at all levels of government to significantly reduce greenhouse gas (GHG) emissions. The City Council recognized the importance of municipal action towards reducing the community’s impact on climate change and, in 2019 adopted a goal of reducing communitywide carbon emissions to 80% below 1990 levels by 2030 and achieving carbon neutrality (zero carbon dioxide emissions) by 2050 or sooner.
These ambitious but achievable goals initiated a range of interdepartmental City projects and programs designed to reduce the environmental impact of emissions from transportation, construction, landfill waste generation, and energy infrastructure (mostly from building emissions). Many new buildings in Santa Monica are utilizing zero emissions electricity sources from rooftop solar and enrollment in the Clean Power Alliance.
Traditionally, carbon emissions have been addressed from the operation of a building but to achieve long term carbon reductions addressing embodied carbon is imperative.
The emissions from embodied carbon in the building sector contribute to global greenhouse gas emissions and have yet to be addressed. A low-carbon concrete policy reduces emissions from the largest contributor to embodied carbon, concrete.
At the local level, the City of Santa Monica is engaged in numerous efforts to reduce citywide Green House Gas (GHG) emissions. These include:
4 of 13
• 2019 Electric-Preferred building code amendment encourages all-electric building design.
• Participating in the Clean Power Alliance offers 100% renewable and carbon-free electricity to customers.
• The EV Charger Reach Code increases the required EV Charging infrastructure in new construction, increasing access to EV charging and encouraging EV adoption.
• The Electrify Santa Monica rebate program incentivizes residents and small businesses to install EV charging stations and convert methane gas appliances to efficient electric alternatives.
• Numerous energy efficiency-related projects and public EV infrastructure projects at municipal sites. Energy savings from four parking structure lighting retrofits in 2021 yielded a 44% average reduction in annual energy usage at those sites.
Low-carbon concrete is an effective policy solution to further reduce emissions in the building sector, as demonstrated by action at the local, county, and state levels below. • In 2019, Marin County adopted a low-carbon concrete ordinance that limits the amount of cement and global warming potential in concrete in all new construction.
• In September 2021, Governor Newsom signed Senate Bill 596 requiring the California Air Resources Control Board (CARB) to develop a strategy for the cement sector in California to reduce greenhouse gas emissions by 40% from baseline levels by 2035 and achieve net-zero by 2045.
• The 2022 California Green Building Standards Code, Title 24, Part 11 includes two voluntary “Reach Codes”, A4.403.2 and A5.405.5, that reduce embodied carbon emissions from concrete.
• In September 2022, the Federal General Services Administration released revised low embodied carbon limits for concrete in all GSA projects. • In 2022, the City of Palo Alto adopted a low-carbon concrete ordinance that reduces the amount of cement and global warming potential in concrete in all new construction.
5 of 13
• In 2022, the City of Santa Monica’s Architecture Services team worked with National Ready Mix Concrete to develop a low-carbon concrete mix to build the Moongate Memorial in Woodlawn Cemetery. This resulted in a 21% reduction in greenhouse gas emissions compared to a standard concrete mixture. • In 2023, the California Building Standards Commission adopted embodied carbon standards, including low-carbon concrete standards, which will take effect for all large commercial buildings over 100,000 square feet and schools over 50,000 square feet in July 2024 under the intervening code cycle.
Based on case studies from concrete suppliers and developers, staff estimate that the low-carbon concrete standards in the proposed ordinance can result in emissions reductions ranging from 14-33% from the baseline in Santa Monica. A comparison of low-carbon concrete thresholds in the CALGreen (Attachment B) shows that Santa Monica would join Marin County and Palo Alto as leaders in the State and country in reducing embodied carbon emissions from concrete without raising the cost of construction.
Discussion
In early 2023, Office of Sustainability and the Environment (OSE) staff began researching possible policy pathways to reduce City embodied carbon emissions. In Spring 2023 the Council asked City staff to report on City efforts to use low-carbon concrete. OSE staff researched existing and developing embodied carbon policies and consulted with staff from other jurisdictions that are implementing embodied carbon policies, concrete industry professionals, and local environmental advocates. This process revealed that a low-carbon concrete policy is the most effective, efficient, and direct pathway to reduce embodied carbon emissions without increasing costs for developers or the City. With the goals of reducing building emissions and establishing a requirement that could be implemented for City and private projects, OSE collaborated with other Public Works and Community Development staff including the City Engineer and City Building Officer to develop ordinance language and began a stakeholder engagement process to gather feedback and support from concrete suppliers who supply to local construction projects.
6 of 13
Stakeholder Outreach & Public Outreach
The compliance levels in the proposed ordinance were developed for the Marin County’s Low-Carbon Concrete ordinance by a stakeholder group of construction, design, and concrete experts. OSE and other Public Works staff built on the initial stakeholder process in Marin County to ensure that local industry experts agreed with and could comply with the ordinance. City staff met with major concrete suppliers, including the supplier currently under contract with Public Works for City projects, to review and discuss the ordinance. Each concrete supplier expressed confidence that they could meet the compliance requirements and demonstrated through concrete mixdesigns or environmental product declarations that they already have the capacity and ability to meet the proposed requirements.
OSE staff conducted a field visit to a housing development in Malibu utilizing low-carbon concrete that meets the proposed ordinance thresholds to see the concrete in use. The general contractor on-site praised the strength of the low-carbon concrete and ease of application. Additionally, OSE and Public Works staff arranged for a concrete industry professional to provide an educational presentation on low-carbon concrete and its applications for Public Works staff.
In January 2024 OSE staff hosted a stakeholder outreach meeting with housing industry professionals including housing developers, architects, affordable housing developers, and structural engineers to review the proposed low-carbon concrete ordinance and provide feedback. Structural engineers on the call indicated that they can and already do work with this material in their designs and asked us to include language to encourage lower carbon cements. Building designers gave helpful feedback on the language of exemptions and increases so the policy is clear and specific. Participants also encouraged staff to develop resources to educate the building community on the new policy requirements.
Also, in January 2024 OSE staff presented the proposed low-carbon concrete ordinance to Climate Action Santa Monica members to receive feedback from community 7 of 13
members. The public was very encouraging and showed strong support for this work and the policy.
On January 22, 2024, the Commission on Sustainability, Environmental Justice, and the Environment passed a motion to support the proposed Low Carbon Concrete Ordinance to reduce global warming emissions from the City’s building sector.
Feedback from stakeholder meetings has been overwhelmingly positive. Concerns about cost and supply impacts have been mitigated by the cost exemption in the ordinance.
Cost Analysis
Case studies of low-carbon concrete projects show that they can generate a cost savings or result in no to low-cost premiums. A Rocky Mountain Institute report (Attachment C) provides case studies showing embodied carbon savings from lowcarbon concrete of up to 33% with less than a 1% cost increase from conventional design. The Low Carbon Initiative has provided a case study (Attachment D) of a residential construction project in Malibu that achieved a 40% reduction in embodied carbon compared to a conventional foundation, with a cost savings of 2% compared to the conventional design. Likewise, the Department of Energy’s Pathways to Commercial Liftoff: Low-Carbon Cement report (Attachment E) provides cost analysis comparing the cost of traditional cement and the available substitutes on the market and finds that the use of substitutes for traditional cement can reduce costs $5 - $20 per ton.
When OSE and Public Works staff conducted stakeholder outreach to three concrete suppliers, each supplier was confident that low-carbon concrete mixes would not increase the cost of concrete.
City of Santa Monica’s Proposed Low-Carbon Concrete Policy Summary Concrete used in Santa Monica must meet one of two compliance requirements, either a Portland Cement Limit or Global Warming Potential Limit, based on the minimum 8 of 13
specified strength of the concrete used in construction for which a permit for construction is issued after the effective date of the ordinance.
Exemptions are minimal and include the following:
• There is a lack of commercially available material necessary to comply with this chapter. The applicant must provide letters from at least two local concrete suppliers confirming the lack of available material to comply; • If the cost of low-carbon concrete is more expensive than the cost of the conventional Portland cement (OPC) mix. The applicant must provide quotes from at least two local concrete suppliers comparing the cost of an OPC mix and equivalent strength low-carbon concrete mix;
• Emergency purchases made in conformance with Santa Monica Municipal Code (SMMC) Section 2.24.240
• This requirement does not apply to pre-packaged proprietary concrete bags used for small quantities (less than 3 yards) or where there is an immediate need for on-site concrete mixing.
Proposed Building Standards Code Amendments
The proposed ordinance adopts the 2022 California Green Building Standards Code (CALGreen) and provides a local amendment to a voluntary measure, or “Reach Code” in Title 24 Part 11 of the California Green Building Standards Code (CALGreen). Cities have the option to adopt increased voluntary requirements proposed in CALGreen that are known as Tier 1 and Tier 2, or they can adopt their own. The proposed ordinance is an adoption of CALGreen with local amendments to enhance and improve the Reach Code. In addition to the proposed CALGreen voluntary Reach Code the ordinance includes several amendments to the 2022 Building Standards Code sections that describe concrete application to amend those sections to include compliance with the proposed CALGreen Reach Code.
The recommended amendments to the 2022 CALGreen code are as follows:
• Section 5.409.3 Product GWP compliance – prescriptive path. Apply the authority of the reach code to all residential and non-residential projects as mandatory. 9 of 13
• Add Table A (below) to 5.409.3 Reach Code to provide two compliance pathways, a Portland Cement Limit and a Global Warming Potential Limit for concrete mixes at minimum specified compressive strengths. o Each concrete application requires different minimum specified compressive strengths. The compliance table (Table A) provides maximum Portland Cement limit or Global Warming Potential limits for compressive strengths. Project designers can use linear interpolation to find compliance limits for compressive strengths not listed on the table. o Global warming potential is a standard data point on Environmental Product Declarations (EPD) for concrete mixes. Project designers can use an EPD to prove compliance with the proposed ordinance. o Concrete suppliers who do not produce EPDs produce Mix Designs, an ingredient list of materials in the concrete, that include the amount of Portland cement. Project designers can use a Mix Design to prove compliance with the proposed ordinance.
o The proposed amendments are an improvement to CALGreen and provide clear and easy to follow maximum allowed cement or global warming potential limits that can achieve emissions reductions.
Table A - Cement and Global Warming Potential (GWP) Limits Portland Cement Limits Global Warming Potential
(GWP) Limits
Minimum specified compressive
strength f’c, psi (1)
Maximum Portland cement
content, lbs/yd3(2)
Maximum Global Warming
Potential (GWP) kg CO2e/m3
up to 2500 362 260
3000 410 289
4000 456 313
5000 503 338
6000 531 356
7000 594 394
7001 and higher 657 433
up to 3000 light weight 512 578
4000 light weight 571 626
5000 light weight 629 675
10 of 13
Notes:
(1) For concrete strengths between the stated values, use linear interpolation to determine Portland cement and/or GWP limits.
(2) Portland cement of any type per ASTM C150, ASTM C595 or ASTM C1157. (3) Project applicants can choose to comply using the Maximum Portland Cement limits OR the Maximum Global Warming Potential limits.
The proposed ordinance also amends sections of the 2022 California Building Standards and Residential Codes that cover concrete applications to include compliance with the proposed pathways in Table A. These code sections are:
• Section 301 General – Green Building Standards Code
o Amend to read: 301.6 Low-carbon concrete requirements new construction. Plain and reinforced concrete installed as part of any project subject to the application of this code shall demonstrate compliance with the requirements of SMMC 8.106.130, the full text of which is herein added to this code by reference.
• Section 1901.2 Plain and Reinforced Concrete – Building Standards Code o Amend to read: Structural concrete shall be designed and constructed in accordance with the requirements of this chapter and ACI 318 as amended in Section 1905 of this code and Santa Monica Municipal Code Chapter 8.106.130. Except for the provisions of Sections 1904 and 1907, and other than compliance with Santa Monica Municipal Code Section
8.106.130, the design and construction of slabs on grade shall not be governed by this chapter unless they transmit vertical loads or lateral forces from other parts of the structure to the soil.
• Section R402.1 Materials for concrete – Residential Code o R402.2.1 Materials for concrete. Materials for concrete shall comply with the requirements of Section R608.5.1, as amended by SMMC Chapter
8.106.130.
• Section R404.1.3 Concrete foundation walls – Residential Code o R404.1.3 Concrete foundation walls. Concrete foundation walls that support light-frame walls shall be designed and constructed in accordance 11 of 13
with the provisions of this section, ACI 318, ACI 332, or PCA 100, as amended by SMMC 8.106.130. Concrete foundation walls that support above-grade concrete walls that are within the applicability limits of Section R608.2 shall be designed and constructed in accordance with the provisions of this section, ACI 318, ACI 332, or PCA 100, as amended by SMMC 8.106.130. Concrete foundation walls that support above-grade concrete walls that are not within the applicability limits of Section R608.2 shall be designed and constructed in accordance with the provisions of ACI 318, ACI 332, or PCA 100, as amended by SMMC 8.106.130. Where ACI 318, ACI 332, PCA 100 or the provisions of this section, as amended by SMMC 8.106.130, are used to design concrete foundation walls, project drawings, typical details and specifications are not required to bear the seal of the architect or engineer responsible for design, unless otherwise required by the state law of the jurisdiction having authority. • Section R506.1 General – Residential Code
o R506.1 General. Concrete slab-on-ground floors shall be designed and constructed in accordance with the provisions of this section or ACI 332, as amended by SMMC 8.106.130. Floors shall be a minimum 3 1/2 inches (89mm) thick (for expansive soils, see Section R403.1.8). The specified compressive strength of concrete shall be as set forth in Section R402.2. • Section R608.5 Materials – Residential Code
o R608.5 Materials. Materials used in the construction of concrete walls shall comply with this section, as amended by, as amended by SMMC
8.106.130
Next Steps
The 2022 California Green Building Standards Code, together with local amendments and required findings to support those local amendments, are presented for Council adoption. The resolution (Attachment F) sets forth findings regarding local climatic, 12 of 13
geological, topographical, and environmental conditions that are required to support the adoption of the local code amendments.
If approved by Council, the proposed amendments must be submitted to the California Building Standards Commission (CBSC). Public notification of the local amendments and the effective date of the building code would be published on the City’s website, and informational notices would be available at the City Hall Permit Counter. Staff will also engage local industry associations and professionals to ensure awareness of and compliance with the new requirements.
Environmental Review
The ordinance is exempt from CEQA pursuant to Section 15308 of the CEQA Guidelines. Section 15308 also provides an exemption for Class 8 projects, which include actions taken by regulatory agencies, as authorized by state or local ordinance, to assure the maintenance, restoration, enhancement, or protection of the environment where the regulatory process involves procedures for the protection of the environment.
The ordinance would require that low emissions carbon concrete would be used in Santa Monica to reduce carbon emissions for the protection of the environment.
Therefore, the ordinance is categorically exempt from CEQA review under CEQA Guideline section 15308.
Financial Impacts and Budget Actions
There is no immediate financial impact or budget action necessary as a result of recommended action. Staff will return to Council if specific budget actions are required in the future.
13 of 13
Prepared By: Peter Roquemore, Sustainability Analyst
Approved Forwarded to Council
Attachments:
A. Santa Monica Climate Action & Adaptation Plan
B. GWP Comparison
C. RMI Embodied Carbon Report
D. LCI Case Study
E. DOE Pathways to Commercial Liftoff: Low-Carbon Cement F. Low-Carbon Concrete Resolution
G. Low-Carbon Concrete Ordinance
H. Written Comments
I. PowerPoint Presentation