Many state and local governments are demanding that the built environment become “green.” Cities and counties are undertaking efforts at the local level to increase energy efficiency and require greater sustainability in buildings and reduce stormwater runoff. Such efforts include:

  • The District of Columbia has adopted green building and energy benchmarking legislation, and is conducting a second round of “greening” its building code.
  • New York City has adopted a Greener, Greater Buildings Plan that will require building energy rating and annual disclosure for larger buildings, as well as energy audits and retro-commissioning of private and large public buildings. Buildings will also be required to meet a New York City Energy Code upon renovation.
  • California cities, such as San Francisco and Los Angeles, have adopted green building ordinances imposing requirements for water and energy conservation, as well as waste reduction.

The 2010 California Green Buildings Standards Code, known as “CalGreen,” is one of the latest examples of these types of measures. CalGreen will set an even higher platform for incorporating “green” into the built environment and standardize the requirements applicable to jurisdictions in California.

As another chapter in California’s effort to adopt climate change mandates affecting the development sector, CalGreen was recently published by the International Code Council as Part 11 of the California Building Standards Code in Title 24 of the California Code of Regulations.1 In August 2010, the California Building Standards Commission (CBSC) released a “Guide to the California Green Buildings Standards Code” (CalGreen Guide), which is intended to provide an introduction to CalGreen.2 The CalGreen Code and accompanying Guide offer new mandates as well as options for California developers anticipating constructing projects beginning in 2011, and also serve as useful resources in and outside California for determining how to reduce greenhouse gas (GHG) emissions from building construction and development.

The CBSC adopted CalGreen on January 12, 2010; it will take effect on January 1, 2011.

CalGreen represents another component in California’s growing toolbox of GHG reduction mandates and is intended to “reduce construction waste, make buildings more efficient in their use of materials and energy, and reduce environmental impacts during and after construction.” CalGreen Guide at 1. As the nation’s first state-level mandatory compilation of green building standards, CalGreen is likely to be looked to as a model for other states interested in developing similar standards.


In December 2009, the California Air Resources Board (CARB) adopted the “Climate Change Scoping Plan: A Framework for Change” (Scoping Plan),3 which sets out a plan for achieving the GHG emission reductions required by the California Global Warming Solutions Act of 2006, or (AB 32). CARB has determined that a 29 percent reduction in GHG emissions, relative to a “business as usual” scenario, must be achieved by 2020 to satisfy AB 32’s mandates. Scoping Plan at 12. Included in the GHG emission reduction measures described in the Scoping Plan is a “Green Building Strategy,” which the Scoping Plan estimates will result in a reduction of 26 million metric tons of carbon dioxide equivalent (MMTCO2e), relative to business as usual, by 2020. Scoping Plan at 59. Although the Scoping Plan does not delineate how much GHG will be reduced as a result of specific green building strategies, it does discuss the anticipated adoption of mandatory green building standards. Scoping Plan at 57. CARB has subsequently estimated that three MMTCO2e will be reduced by 2020 as a result of CalGreen’s mandatory provisions. CalGreen Guide at 5. This represents approximately 1.8 percent of the total 169 MMTCO2e the state must reduce by 2020 from a business as usual scenario in order to satisfy AB 32’s mandates.

CalGreen applies to many types of residential and non-residential buildings throughout California. It includes mandatory provisions as well as two tiers of voluntary provisions for both types of buildings. Incorporation of sufficient voluntary measures entitles a building to qualify as either Tier 1 or Tier 2. See CalGreen Guide at 7-8. A local government may choose to adopt the Tier 1 or Tier 2 provisions as mandatory. Otherwise, compliance with these provisions is purely voluntary. Like the Leadership in Energy and Environmental Design (LEED) certification that is widely used nationwide to indicate a building’s environmental sensitivity, Tier 1 or Tier 2 status would be a purely honorary title indicating the extra commitments made to improve the energy efficiency and decrease the GHG emissions associated with a building.

CalGreen sets minimum standards that must be applied to all applicable buildings throughout the state. Cities and counties are allowed to adopt more restrictive green building standards, including mandatory compliance with the Tier 1 or Tier 2 provisions. However, the locality must make specific findings that such standards are reasonably necessary because of local climate, geological, topographical, or environmental conditions; and various filings must be made with the CBSC. See CalGreen Guide at 7; CalGreen § 101.7. As a practical matter, the several dozen local governments that have already adopted green building ordinances will need to ensure their ordinances comply with CalGreen’s minimum requirements, if they intend to still enforce them. And, to the extent they exceed CalGreen’s minimum standards, the cities and counties will need to adopt the necessary findings and follow the new prescribed administrative filing process with CBSC. These requirements will likely have the effect of minimizing the proliferation of local green building standards.


CalGreen applies to both residential and non-residential buildings, as noted above. “Residential buildings” are buildings of three stories or less, including motels, hotels, apartments, and one- and two-family dwellings or townhouses, as well as other structures specified in Section 104 of CalGreen. CalGreen Guide at 6. “Non-residential buildings” include state-owned buildings, state university and community college buildings, and privately-owned buildings used for retail, office and medical services, as well as other specified building categories. CalGreen Guide at 6.

Mandatory provisions for both residential and non-residential buildings are divided into five categories: site development; energy efficiency; water efficiency and conservation; material conservation and resource efficiency; and environmental quality. See CalGreen, Chapters 4 and 5. The mandatory provisions in each category are similar for residential and non-residential buildings, though the non-residential building requirements tend to include additional specifications and apply to more fixtures and systems.

Key requirements applicable to both types of buildings include:

20 percent mandate to reduce indoor water use

50 percent mandate to recycle or reuse nonhazardous construction and demolition debris

inclusion of automated outdoor irrigation controls

Non-residential buildings have additional requirements including 100 percent reuse or recycling of soils and land clearing debris; and building commissioning for buildings larger than 10,000 square feet, or systems testing and adjusting for buildings less than 10,000 square feet.

Notably, CalGreen does not require additional energy efficiency standards beyond those promulgated by the California Energy Commission (CEC), though the Code does note that CEC believes that code-compliant “green buildings” should achieve at least 15 percent greater energy efficiency than required by the CEC Title 24 standards.

Voluntary provisions for residential and non-residential buildings cover a broader range of topics. See CalGreen, Appendices A4 and A5. For example, site selection criteria is not included in the mandatory code sections; however, buildings located in infill, greyfield or brownfield sites get credit toward qualifying for Tier 1 or Tier 2 status. Additional voluntary criteria that are not included in the mandatory provisions include site preservation; deconstruction and reuse of existing material; site development restrictions such as building orientation, topsoil protection, landscape design and cool roofs; water reuse systems; foundation system requirements; framing technique requirements; and management for water resistance and moisture levels. Finally, voluntary provisions include additional commitments to energy efficiency (at least 15 percent beyond CEC requirements for a Tier 1 building and 30 percent for a Tier 2 building), more stringent water-conserving fixtures and systems, prescriptions for construction material selection, increased waste disposal commitments, and various limitations relating to building materials such as recycling content and use of renewable materials. As described above, cities or counties may elect to adopt Tier 1 or Tier 2 provisions as mandatory, upon making the necessary findings. Or, a developer may simply elect to include sufficient voluntary provisions to qualify for Tier 1 or Tier 2 status.


By adopting this mandatory set of green building standards, California continues to take a leadership role in reducing GHG emissions and improving energy efficiency. With CalGreen’s specific requirements clear, developers can plan ahead for how they will implement mandatory measures and elect (or be required by local government) to implement Tier 1 or Tier 2 measures. We continue to recommend that such measures be included in project designs (e.g., as a Sustainability Plan) and also incorporated into relevant topical sections of Environmental Impact Reports (EIRs) prepared pursuant to the California Environmental Quality Act as project design features and/or mitigation measures. Many of these new CalGreen mandates have co-benefits relating to other environmental impacts studied in EIRs, such as reducing water demand, criteria air pollutants and waste disposal. We also recommend that the benefits of these measures be quantified where feasible, since these will help projects reduce GHG emissions by 29 percent below business as usual, consistent with the Scoping Plan framework. CalGreen will likely be looked to by all players in the California development process as setting both a mandatory floor, and potentially a Tier 2 ceiling, for green development practices. Given the size of the California building market, CARB and others also expect that CalGreen provisions for building materials and handling practices will influence building product manufacturers and practices in other states.