Pursuant to California Health and Safety Code Section 17958.2(a), the City Council hereby finds the following modifications to the California Building Standards Code provisions regulating allowable mix design and materials for plain and reinforced concrete are reasonably necessary. This is because Sausalito experiences climatic seasonal reduction in vegetative moisture content, combined with heavily populated steep terrain, which presents increased wildfire risk to our residents from carbon-induced global warming; and is also bordered by sea water on much of its territorial border and subject to direct adverse local impact from sea-level rise as the result of construction-related contributions to climate change, including significant carbon emissions from cement production.
The purpose of this chapter is to provide practical standards and requirements for the composition of concrete, as defined herein, that maintains adequate strength and durability for the intended application and at the same time reduces greenhouse gas emissions associated with concrete composition. This code includes pathways for compliance with either reduced cement levels or lower-emission supplementary cementitious materials.
(Ord. 05-2026, 4/21/2026)
For the application of this chapter the following definitions shall apply:
Concrete:
Concrete is any approved combination of mineral aggregates bound together into a hardened conglomerate in accordance with the requirements of this code.
Environmental Product Declaration (EPD):
EPDs present quantified environmental information on the life cycle of a product to enable comparisons between products fulfilling the same function. EPDs must conform to ISO 14025, and EN 15804 or ISO 21930, and have at least a "cradle to gate" scope (which covers product life cycle from resource extraction to the factory).
Upfront Embodied Carbon (Embodied Carbon):
The greenhouse gasses emitted in material extraction, transportation and manufacturing of a material corresponding to life cycle stages A1 (extraction and upstream production), A2 (transportation), and A3 (manufacturing). Definition is as noted in ISO 21930 and as defined in the Product Category Rule for Concrete by NSF dated February 22nd, 2019.
(Ord. 05-2026, 4/21/2026)
Compliance with the requirements of this chapter shall be demonstrated through any of the compliance options in Sections 8.04.040 through 8.04.070.
Table 8.04.030 Cement and Embodied Carbon Limit Pathways
Cement limits for use with any compliance method Sections 8.04.040 through 8.04.070
Embodied Carbon limits for use with any compliance method Sections 8.04.040 through 8.04.070
Minimum specified compressive strength f'c, psi (1)
Maximum ordinary Portland cement content, lbs/yd3(2)
Maximum embodied carbon kg CO2e/m3, per EPD
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
Notes
(1)
For concrete strengths between the stated values, use linear interpolation to determine cement and/or embodied carbon limits.
(2)
Portland cement of any type per ASTM C150.
(Ord. 05-2026, 4/21/2026)
Cement content of a concrete mix using this method shall not exceed the value shown in the Table 8.04.030. Use of this method is limited to concrete with specified compressive strength not exceeding 5,000 psi.
(Ord. 05-2026, 4/21/2026)
Total cement content shall be based on total cement usage of all concrete mix designs within the same project. Total cement content for a project shall not exceed the value calculated according to Equation 8.04.050.
Equation 8.04.050:
Cemproj < Cemallowed
where
Cemproj=ΣCemnVnandCemallowed=ΣCemlimVn
and
n = the total number of concrete mixtures for the project
Cemn = the cement content for mixturen, kg/m3 or lb/yd3
Cemlim= the maximum cement content for mixturen per Table 8.04.030, kg/m3 or lb/yd3
Vn = the volume of mixturen concrete to be placed, yd3 or m3
Applicant can use yd3 or m3 for calculation, but must keep same units throughout
(Ord. 05-2026, 4/21/2026)
Total embodied carbon (ECproj of all concrete mix designs within the same project shall not exceed the project limit (ECallowed) determined using Table 8.04.030 and Equation 8.04.050.
(Ord. 05-2026, 4/21/2026)
A. 
Cement and Embodied Carbon Limit Allowances. Cement or Embodied Carbon limits shown in Table 8.04.030 can be increased by 30% for concretes demonstrated to the Building Official as requiring high early strength. Such concretes could include, but are not limited to, precast, prestressed concrete; beams and slabs above grade and shotcrete
B. 
Approved Cements The maximum cement content may be increased proportionately above the tabulated value when using an approved cement, or blended cement, demonstrated by approved EPD to have a plant-specific EPD lower than 1040 kg CO2e/metric ton. The increase in allowable cement content would be (1040/plant=specific EPD) %.
(Ord. 05-2026, 4/21/2026)
A. 
Hardship or Infeasibility Exemption. If an applicant for a project subject to this chapter believes that circumstances exist that make it a hardship or infeasible to meet the requirements of this chapter, the applicant may request an exemption as set forth below. In applying for an exemption, the burden is on the applicant to show hardship or infeasibility. The applicant shall identify in writing the specific requirements of the standards for compliance that the project is unable to achieve and the circumstances that make it a hardship or infeasible for the project to comply with this chapter. Circumstances that constitute hardship or infeasibility may include, but are not limited to the following:
1. 
There is a lack of commercially available material necessary to comply with this chapter;
2. 
The cost of achieving compliance is disproportionate to the overall cost of the project;
3. 
Compliance with certain requirements would impair the historic integrity of buildings listed on a local, state or federal list or register of historic structures as regulated by the California Historic Building Code (Title 24, Part 8).
B. 
Granting of Exemption. If the Building Official determines that it is a hardship or infeasible for the applicant to fully meet the requirements of this chapter and that granting the requested exemption will not cause the building to fail to comply with the California Building Standards Code, the Building Official shall determine the maximum feasible threshold of compliance reasonably achievable for the project. In making this determination, the Building Official shall consider whether alternate, practical means of achieving the objectives of this chapter can be satisfied. If an exemption is granted, the applicant shall be required to comply with this chapter in all other respects and shall be required to achieve the threshold of compliance determined to be achievable by the Building Official.
C. 
Denial of Exception. If the Building Official determines that it is reasonably possible for the applicant to fully meet the requirements of this chapter, the request shall be denied and the applicant shall be notified of the decision in writing. The project and compliance documentation shall be modified to comply with the standards for compliance.
D. 
Appeal. Any aggrieved applicant or person may appeal the determination of the Building Official regarding the granting or denial of an exemption or compliance with any other provision of this chapter. An appeal of a determination of the Building Official shall be filed in writing and processed in accordance with the provisions of this code and the California Building Standards Code for appeals.
(Ord. 05-2026, 4/21/2026)