History of the California Green Building Standards Code (CALGreen)
The California Green Building Standards Code, also known as CALGreen, is Part 11 of Title 24 of the California Code of Regulations. It is the first-in-the-nation green building standards code and its history, although relatively short, is significant.
It began in 2007, when CBSC was directed to develop green building standards to help meet the goals of California’s landmark climate initiative—Assembly Bill 32. AB 32, Chapter 488, Statutes of 2006, added Division 25.5 to the California Health and Safety Code, and is known as the California Global Warming Solutions Act. AB 32 established law requiring a comprehensive program for the reduction of greenhouse gases to 1990 levels by the year 2020. Notably, AB 32’s Scoping Plan identified buildings as the second largest source of California’s greenhouse gas emissions.
Subsequent to AB 32, Senate Bill 1473, Statutes of 2008, specifically gave CBSC the authority to develop green building standards for nonresidential occupancies for which no other state agency has authority, such as commercial properties and state buildings. Other state agencies that have authority to develop green building standards are the Division of the State Architect for schools and community colleges, the Department of Healthcare Access and Information (HCAI, formerly the Office of Statewide Health Planning and Development) for hospitals and various other health facilities, and the Department of Housing and Community Development (HCD) for residential occupancies.
In response to these legislative mandates, CBSC worked closely with the other state agencies to create new green building standards, with the goals of:
• Reducing greenhouse gas emissions from buildings
• Promoting environmentally responsible, cost-effective, healthier places to live and work
• Reducing energy and water consumption
• Responding to the environmental directives of the administration
State agency representatives, industry stakeholders and interested parties were enthusiastic contributors to the initial code development process and remain active participants in the evolution of CALGreen measures today. It is also worth noting that in recent years other code development organizations around the nation—and the world—have begun to put forth their own sustainable building codes modeled after CALGreen.
The first edition of CALGreen contained only voluntary measures and was published in 2008 with an effective date of August 2009. It established Administration, Definitions and Green Building chapters and created five key sustainable construction divisions:
• Division #1 - Planning and Design
• Division #2 - Energy Efficiency
• Division #3 - Water Efficiency and Conservation
• Division #4 - Material Conservation and Resource Efficiency
• Division #5 - Environmental Quality
Many of the original voluntary green building standards became mandatory in the 2010 CALGreen edition, which went into effect in January 2011. The green code now ensured that new construction projects in California would be built in compliance with sustainable construction practices.
To make the code more user-friendly, the 2010 edition was redesigned to have separate chapters for residential and nonresidential occupancies—Chapter 4 for residential and Chapter 5 for nonresidential. And, in addition to the mandatory green building standards in chapters 4 and 5, voluntary options for more stringent standards were provided in appendix chapters. Appendix A4 has voluntary residential green standards, and Appendix A5 has voluntary nonresidential green standards. Additionally, Appendix A6.1 contains voluntary standards for health facilities.
The provisions in the appendix chapters contain Tier 1 and Tier 2 enhanced sustainable building standards. These tiers provide designers and jurisdictions the opportunity to go beyond the minimum mandatory requirements to promote the use of design and construction concepts that minimize the building’s impact on the environment and promote a more sustainable design. Tier 1 requirements are more stringent than the base mandatory CALGreen provisions, and Tier 2 achieves an even higher standard. Local governments may adopt ordinances that make tier options mandatory in order to meet their community’s sustainability goals. Refer to the Guide for Local Amendments of Building Standards for additional information.
There are tier options for every division of CALGreen, but only certain mandatory measures that can be made more restrictive are provided in the tiers. For instance, excavated soil and land clearing debris is already required to be 100% reused or recycled, so this provision can’t be made more stringent.
To make it easier for design professionals and building officials to apply and enforce the mandatory and voluntary measures, beginning in 2010 two valuable resources were developed for code users to accompany each new edition of CALGreen.
First, comprehensive guidebooks covering CALGreen regulations were developed by HCD (residential) and CBSC (nonresidential). The guides are published for each new edition of CALGreen and offer explanations of the intent, compliance methods, and enforcement suggestions for each section of the code. Links to published guides can be found on the CALGreen webpage.
Additionally, non-regulatory checklists were also developed by the code’s authors. The current checklist format was published in the 2016 edition of CALGreen, after refinement of initial designs in the 2010 and 2013 editions. Some jurisdictions even require the checklists to be submitted with plans to ensure compliance with CALGreen regulations.
Another significant change to CALGreen was the inclusion of triggers for additions and alterations to existing buildings undergoing an addition of 1,000 square feet or more, or an alteration that has a permit valuation of $200,000 or more. The intent of this code change in the 2013 edition was to capture a greater number of California’s buildings and to increase sustainable construction in the state.
Between 2010 and 2022, continuous updates and additions have been made to CALGreen, including water conservation and recycling, electric vehicle infrastructure and charging, and changes intended to eliminate conflicts with the California Energy Code, which is Part 6 of Title 24. For more details of code changes over time, see the Guide to the 2022 California Green Building Standards Code – Nonresidential.
On July 11, 2018, the California Air Resources Board announced in a press release that “greenhouse gas pollution in California fell below 1990 levels for the first time since emissions peaked in 2004 – an achievement roughly equal to taking 12 million cars off the road or saving 6 billion gallons of gasoline a year.” The development of CALGreen has been an important step toward more efficient and responsible building design which helped California meet the greenhouse gas reduction goal ahead of schedule.
This accomplishment has not halted the ongoing development of CALGreen codes to increase sustainable building practices in new construction—and some additions and alterations—in California. During each code adoption cycle, CBSC and the other agencies work together with stakeholders to further the sustainability and climate goals of California and lead the world in developing green building codes.
For more information about CBSC’s historical activities and developments, visit the History of the California Building Standards Commission webpage.