In 2009, the California Green Building Standards Code, or CALGreen, became law, ushering in sweeping changes for the residential and commercial construction industry throughout the Golden State. The mandatory building standards code, updated every three years, sets minimum requirements for how structures are designed and built and which materials can be used. The first of its kind in the nation, CALGreen building requirements will undoubtedly have a significant and lasting impact on the environment and public health. Aside from the resources saved and the reduction in air and water pollution, people who live or work in these new or remodeled buildings will do so in healthier environments.

Recycle, Reuse, and Reduce for a Better Tomorrow

When a commercial or residential building is demolished, any nonhazardous or insoluble materials produced must be recycled or reused to reduce construction waste by at least 65%. These materials include concrete, asphalt, steel, brick, glass wallboard, lumber, gypsum, and pipe. Building materials with any visible signs of water damage cannot be used for new construction, and if wall and floor framing materials exceed 19% moisture content, they cannot be enclosed. In addition, insulation materials that are visibly wet or have high moisture content must be replaced or allowed to dry out before being installed in walls or floors.

To cut down on water pollution, water containing construction debris or any contaminants is prohibited from entering the storm drain system. To minimize the heat island effect, a result of asphalt and concrete increasingly replacing trees and vegetation and a growing issue in urban areas, new hardscape must contain heat reflective properties so that they reflect the sun’s heat rather than absorb it. Reducing the heat island effect helps diminish surface and the overall air temperature, air and water pollution, and summertime energy demand.

Building Materials and Volatile Organic Compound (VOC) Limits

Due to the increasingly toxic nature of many VOCs, California has enacted new regulations to limit VOC emissions from a number of commercial products in the building industry. VOCs are gases from products or processes released into the air. In addition to contributing to air pollution, exposure to harmful VOCs can cause everything from eye and throat irritation to respiratory issues and lung damage; in some cases, harmful VOCs can even cause cancer.Products that must comply with VOC limits include architectural paints and coatings, adhesives, caulks, and sealants, as well as carpets, rugs, and cushions. When installing resilient flooring, a minimum of 80% of the floor area must comply with VOC limits. New restrictions on formaldehyde content in materials such as particle board, medium-density fiberboard, hardwood plywood, and other related products have also been imposed. Furthermore, VOC-emitting and odorous materials are now required to be stored sans packaging offsite for a period of time to allow the safe dispersion of VOCs and odors.

New Rules for Plumbing, Heating, and Cooling Systems

As California grapples with the longest drought on record, CALGreen has introduced restrictions to address the state’s dwindling water supply. Efficient water use for both residential and commercial buildings is vital now more than ever.

To conserve water usage by 20% for new builds, the flow rate of all plumbing fixtures has been modified to meet this new standard. If a shower has more than one shower head, it must be installed so that only one showerhead can be used at a time. Water conservation is also encouraged for existing commercial and residential buildings, with rebates available in many areas to replace existing plumbing fixtures. Outdoor irrigation systems also play a critical role in water conversation and must have sensors that have either weather or soil-based controllers.

To cut down on fine particulate pollution, wood-burning fireplaces, stoves, and pellet stoves are banned in new construction. Fireplaces in new builds must be the sealed direct vent variety. It’s also worth noting that when a Spare the Air Alert is in effect, it is prohibited to operate existing fireplaces, woodstoves, pellet stoves, and outdoor firepits. Additionally, during construction, all duct openings must be covered until the final start-up of the structure’s heating and cooling system.

Electric Vehicle (EV), Solar Energy, and Home Appliance Requirements

California continues to lead the way in enacting laws for clean transportation and energy to combat climate change.

In an effort to reduce greenhouse gas emissions and criteria air pollutants, California now requires that all new residential and commercial buildings be EV capable. Per the CALGreen building code, for residential buildings (single-family homes, townhomes, or duplexes), each dwelling must have a listed raceway accommodating a dedicated 208/40-volt branch circuit.

For multifamily buildings, at least 10% of the total parking spaces must be EV capable (if guest parking is offered, at least one space must be EV capable). For commercial buildings, the EV capable parking spaces required are based on the total number of parking spaces, e.g., for a parking lot with 76 to 100 spaces, five spaces must be EV capable.

A national leader in clean energy policy and implementation, California is the first state to require solar for new residential buildings. For new homes, ADUs, and major remodels and additions, the installation of photo voltaic solar energy systems is now mandatory. For rooftop solar installations, an area of at least 250 sq. ft. must be designated for future electric solar panels and connected to a conduit terminating at a future subpanel. In addition to the solar requirements for new builds, all appliances must meet Energy Star requirements; this includes bathroom exhaust fans, which must also be controlled by a humidistat. Likewise, whole-house ventilation systems must provide air changes within a building for better air quality.

Since CALGreen building codes are California law, building contractors must provide documentation proving all green requirements have been met and required building materials used. Similarly, contractors must also provide the building owner with an operation and maintenance manual at the end of construction.

As California continues to inch toward a more sustainable future, the design and building industry must do its part. As more people move to California and with no end in sight to the worst drought on record, efficient water use in both residential and commercial buildings is critical. Equally important to preserve the environment and reduce pollution is energy efficiency via clean energy sources as well as recycling and reusing construction materials to preserve resources. Establishing minimum requirements for sustainable practices in new construction may seem costly or cumbersome now, but these innovative and forward-thinking practices will indeed make environmental and financial sense later.


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The Agulneks, RLB client

“Richard Blumenberg is such a talented architect; I hardly know where to begin. Richard completely designed and rebuilt our home. We never interviewed any other architects.

— Holley and Bob Agulnek


RLB Architecture is a high-end architecture and design firm that provides custom design, planning, drafting, and construction administration services for projects in the Pacific Palisades, Brentwood, Beverly Hills, Bel Air, Malibu, Santa Monica, and other Westside communities. Richard L. Blumenberg is the proprietor.


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RLB Architecture
15200 Sunset Bl, #201
Pacific Palisades, CA 90272
(310) 459-0244