Low Carbon Concrete Code
The production and supply of materials used in buildings cause greenhouse gases. Globally, concrete is estimated to be responsible for 6-10% of total emissions. Through mix designs, the emissions per cubic yard of concrete can be lowered. Typically, this includes substitutes for cement that come from recycled materials.
Local governments have the authority to adopt building code amendments to require concrete mixes with lower greenhouse gas emissions impacts to produce. In November 2019, the County of Marin was the first jurisdiction to pass a low carbon concrete code amendment. Their code development process included a regional stakeholder working group and the creation of tools to help other jurisdictions adopt similar code amendments. This effort was funded through a Climate Protection Grant from the Bay Area Air Quality Management District.
Click here to visit the County of Marin's website documenting their code amendment adoption.
Code Amendment Toolkit
This toolkit supplies background information and justification for a code amendment, and template language based on the Marin County adoption. It also contains implementation resources, like compliance forms and sample specifications for compliant mixes.
This summary document outlines the process of developing and adopting the Marin County code amendment. It highlights lessons learned and keys to success.
Marin County Process Summary
County of Marin presentation to the BAAQMD Climate Protection Committee, December 2019
Marin County BAAQMD CPC presentation
Why is it important to address concrete?
Visit Architecture 2030's Materials Palette website to learn more: www.materialspalette.org/concrete
Industry documents highlighting low carbon concrete:
- CalTrans Activities to Address Climate Change (external link, PDF)
- CalTrans 21st Century Concrete Guidelines (PDF) which compares performance outcomes from various low carbon options. See page 17 (25th page of the PDF) for table showing the effects of several cement substitutes on specific performance variables.
- NRMCA Performance Based Specification Guidance (PDF) on how to specify low carbon concrete using performance versus prescriptive standards
- Central Concrete Low Carbon Concrete Specification Guide (PDF) from the largest concrete supplier in the state
Background data on setting the thresholds in the Marin County code language.
Background - GWP benchmarking.pdf
Marin Co Ordinance_Low Carbon Concrete Code.docx
Marin County staff report
Marin Co Low Carbon Concrete Staff Report.docx
Compliance forms (currently being revised in Marin County)
Low Carbon Concrete Compliance Form (GWP Path).docx
Low Carbon Concrete Compliance Form (Cement Limit Path).docx
Sample mix specifications for nonresidential projects
Sample Nonresidential Specifications
Sample mix specifications for residential projects
Sample Residential Specifications
The BAAQMD funded project included technical assistance for four Bay Area projects to specify low carbon concrete mixes. Below are brief case study descriptions (PDF downloads).
- Berkeley Way - BRIDGE Housing multifamily project
- Wurster House - historic single family renovation
- Dublin Garage - municipal parking structure
- Tech campus - flatwork in plazas of two tech campuses
Questions & Comments
Send questions, request for assistance, and comments to improve the toolkit to: firstname.lastname@example.org.
This toolkit was funded through a Climate Protection Grant from the Bay Area Air Quality Management District. The opinions, findings, conclusions, and recommendations are those of the author and do not necessarily represent the views of the District. The District, its officers, employees, contractors, and subcontractors make no warranty, expressed or implied, and assume no legal liability for the information in this report.