During any building design, construction, or remodeling project in the State of California, you’ll hear architects, contractors, and folks at the permit desk refer to “Title 24.”

Title 24 is the California Building Standards Code, which governs all aspects of building construction. Included in the Code, Part 6, are standards mandating energy efficiency measures in new construction.

When talking about energy efficiency, people often just say “Title 24” to refer to “Title 24, Part 6, of the California Code of Regulations: California's Energy Efficiency Standards for Residential and Nonresidential Buildings.”

California’s first Title 24 Energy Efficiency Standards were established in 1978 in response to a legislative mandate to reduce California's energy consumption. Since 1978, Title 24 standards have been updated several times in response to the development of new energy efficiency technologies and methods. The energy efficiency requirements in Title 24 are mandated to be “cost-effective.”

Title 24 applies to new construction, as well as additions and modifications to existing buildings. There are different requirements by building type (especially residential versus nonresidential buildings) and climate zone.

Title 24 standards DO cover:

• Building envelope (walls, roofs, windows, insulation)
• Heating and cooling (HVAC) systems
• Water heating systems
• Lighting (both indoor and outdoor)

Title 24 standards DO NOT cover:

• Site design/building configuration (except some limits on west-facing glass due to building orientation)
• Effects of topography or landscaping
• No distinction between large or small buildings (all calculations on a per square foot basis)
• No credit for self-generation (such as solar electric systems)
• Manufacturing, industrial, or agricultural processes (except for lighting)
• No credit for “green” building elements such as recycled content, low toxicity, etc.

Performance vs. Prescriptive Method of Compliance: Title 24 requires certain minimum features to be installed in new construction (mandatory measures) and then allows the builder to choose either a prescriptive or performance path to complete the energy budget portion of the efficiency requirements in construction. The prescriptive path is simple but inflexible; the performance path, though more complex, offers the builder wide latitude in designing the best home for the market.

The performance path allows trade-offs between different building components (wall, roof, windows, infiltration, equipment, etc.), as long as the overall building energy consumption is shown to be within the maximum allowable values of kBTU/ft2. These trade-offs are determined either through hourly computer simulations or derived from simulation results. Title 24 consultants are often used to help projects navigate the compliance process.

Since being first adopted, the Title 24 efficiency standards (along with standards for energy efficiency in appliances) have helped Californians save more than $56 billion in electricity and natural gas costs, along with reducing pollution and other adverse impacts from consumption of fossil fuels.