The construction industry has long been a significant contributor to global carbon emissions. While significant strides have been made in reducing operational carbon—the emissions produced during the use phase of a building’s life—embodied carbon, which includes the emissions from manufacturing and transporting construction materials, is now receiving the attention it deserves. To address this, California has updated CALGreen, the first mandatory green building standards code in the United States, with new requirements in effect as of July 1, 2024. These updates aim to reduce the environmental impact of buildings by focusing on embodied carbon.
What is CALGreen?
CALGreen, also known as Title 24 of the California Code of Regulations, is an initiative designed to reduce the environmental footprint of buildings. It requires non-residential buildings over 100,000 square feet and schools over 50,000 square feet to meet specific sustainability criteria. A key aspect of CALGreen is its emphasis on reducing embodied carbon — the carbon dioxide emissions associated with the production, transportation, and installation of building materials.
One Click LCA is actively supporting the industry by providing tools that streamline the process of measuring and managing embodied carbon. Our software is designed to help AEC professionals conduct thorough life-cycle assessments and generate accurate environmental product declarations (EPDs), aligning with CALGreen’s stringent requirements.
Pathways to compliance
To comply with CALGreen, buildings must adhere to one of three pathways, each offering a different approach to reducing environmental impact:
- Building reuse: This pathway encourages the reuse of at least 45% of an existing structure and its exterior. By repurposing existing buildings, this method minimizes the need for new materials and reduces construction waste.
- Performance: This pathway involves conducting a whole building life-cycle assessment (WBLCA) to demonstrate a 10% reduction in embodied carbon compared to a baseline model. Embodied carbon is a critical factor in a building’s overall carbon footprint, making this reduction crucial for sustainability. One Click LCA’s software can automate much of the LCA process, making it easier for professionals to achieve and verify these reductions.
- Prescriptive: Under this pathway, builders must document environmental product declarations (EPDs) for specified materials. EPDs provide detailed information about the environmental impact of materials, enabling informed decision-making during the design and construction phases. One Click LCA’s comprehensive EPD database helps in selecting materials that meet CALGreen’s prescriptive path criteria.
The importance of life-cycle assessments (LCAs)
A life-cycle assessment (LCA) is a comprehensive method for evaluating the environmental impacts associated with all stages of a building’s life, from raw material extraction through construction, use, and disposal. In the context of CALGreen, LCAs play a vital role in the performance pathway, helping to quantify and reduce embodied carbon. One Click LCA is providing the sector with robust LCA tools that integrate seamlessly with BIM models and other design tools, facilitating accurate and efficient assessments.
Implementing the CALGreen requirements
The new CALGreen measures will require architects, engineers, and builders to adopt a holistic approach to carbon management. The requirements include:
- Cradle to grave assessment: LCAs must consider the entire life-cycle of the building materials, excluding operational energy but including all other stages. Our software supports this comprehensive analysis by providing detailed data and easy-to-use interfaces.
- Reference baseline: The baseline for comparison must consist of the same type of materials, size, function, complexity, and location as the proposed project. One Click LCA helps create accurate baselines by using a vast database of industry standards and benchmarks.
- 10% reduction: The mandatory measure requires a 10% reduction in embodied carbon from this baseline. Voluntary tiers offer incentives for achieving 15% and 20% reductions. Our tools facilitate tracking and documenting these reductions throughout the project lifecycle.
- Software compliance: The LCA software used must comply with specific ISO standards to ensure consistency and accuracy in reporting. One Click LCA is fully compliant with these standards, ensuring that all assessments meet regulatory requirements.
The role of policy in driving change
The introduction of CALGreen is part of a broader movement to reduce embodied carbon in the construction industry. Various policies and initiatives at the federal and state levels are contributing to this effort:
- Buy Clean California Act: This act sets global warming potential limits for specific building materials used in state projects.
- Inflation Reduction Act (IRA): The IRA includes significant funding for climate initiatives, supporting the development and adoption of low-carbon materials.
One Click LCA supports these initiatives by providing the tools necessary for compliance and promoting best practices in sustainable construction.
Future outlook
California’s move to regulate embodied carbon sets a precedent for other states and countries. By focusing on the entire life-cycle of building materials, CALGreen addresses a critical aspect of sustainability that has often been overlooked. This regulation is expected to drive innovation in the construction industry, encouraging the development of new materials and technologies that reduce carbon emissions.
As the construction industry adapts to these new standards, the collaboration of architects, engineers, builders, and policymakers will be crucial. The adoption of LCAs and other sustainable practices will not only help meet CALGreen requirements but also contribute to a more sustainable and resilient built environment.
One Click LCA is committed to supporting the industry through this transition, providing the tools and expertise necessary to meet CALGreen’s ambitious targets. By setting high standards and leading by example, California is paving the way for a more sustainable future in the construction industry and beyond.
(posted 7/25/24)
About the Author
Amarpreet Singh, LCA & Circular Economy Expert | Building Decarbonization
Building & Infrastructure LCA, EPD solutions, One Click LCA
Amarpreet Singh has been committed to advancing sustainability across multiple industries throughout his career. His work in advancing waste management practices in 5 countries led him to the understanding that policy changes must be accompanied by fundamental changes in human behavior. He established over 500 commercial food waste composting installations and helped scale a zero-waste products start-up in India. His current focus is on decarbonizing the construction industry in California using life-cycle assessments, life-cycle costing, and EPDs with One Click LCA.
