When it comes to building codes across the nation, California’s Title 24 can be some of the most thorough. Understanding California’s building codes is key to an efficient construction project that will be fully code-compliant and will pass inspection and commissioning. Learn more about California’s building code requirements for insulation so you will be prepared.
What is Title 24?
Most discussions concerning the California building code start by mentioning Title 24. Used as the basis for construction in California, the California Title 24 Building Energy Efficiency Standards are designed to ensure new and existing buildings achieve energy efficiency and preserve outdoor and indoor environmental quality. Title 24 applies to the construction of, additions and alterations to, residential and nonresidential buildings except for jails and prisons. This progressive set of building codes and standards often leads the nation in requirements for energy efficiency.
How Did Title 24 Start?
The Warren-Alquist Act established the California Energy Commission (CEC) in 1974, which ultimately developed and adopted the energy efficiency standards that became Title 24. The codes are updated over time, typically every three years, to incorporate new energy efficiency technologies and construction methods.
Title 24 Requirements
Almost all construction in California must adhere to the requirements laid out in Title 24. A lack of knowledge of the standards does not qualify as an excuse for not adhering to them and will result in delays and increased costs on construction projects. Certain requirements or measures within Title 24 are either mandatory or prescriptive.
Mandatory Requirements
These requirements must always be met for a construction project. They can not be traded off. These requirements set the baseline for construction in the state of California.
Prescriptive Requirements
The predefined efficiency requirements may supersede mandatory requirements. The requirements can be different for new construction, additions, and alterations. Prescriptive requirements allow for more flexibility.
Two Paths for Compliance
Seeking compliance under Title 24 offers two common approaches: the prescriptive approach and the performance approach.
Prescriptive Approach
Most common for alterations and non-residential construction projects, this approach is very simple. The prescriptive approach allows for no trade-offs. The construction project must match the standard building baseline.
Performance Approach
A much more flexible approach, the performance approach does allow for trade-offs. All mandatory requirements must still be met and CEC-approved software must be used in the design process. Homes and buildings designed under the performance approach must have lower energy design ratings than the standard building design, meaning they must be more energy efficient than the standard building.
Title 24 and Insulation
Insulation plays an important role in Title 24 due to the impact insulation has on an overall building’s energy efficiency. Title 24 sets the minimum amounts of insulation in terms of U-factor. The U-factor is a measure of the heat transmission through a given thickness of material. The U-factor is simply the inverse of the R-value (1/R).
Mandatory Requirements for Insulation
All insulation must be certified to California Quality Standards for Insulation Materials by the California Department of Consumer Affairs. Certain insulation materials are not allowed in California that are allowed in other parts of the U.S. Foam insulation made from formaldehyde is restricted under Title 24. Fire retardants must all be exposed on surfaces and installed according to code.
Roof and Ceiling Insulation
Title 24 requires that insulation be placed in direct contact with the infiltration barrier. If using a ventilated attic design, this makes the ceiling drywall the infiltration barrier.
When insulation is at the roof, no openings or vents into the unconditioned space are allowed between the ceiling and roof. The maximum U-factors listed in Title 24 for roof and ceiling assemblies are:
Roof and ceiling - metal building: 0.098
Roof and ceiling - wood framed and other: 0.075
Wall Insulation
The insulation requirements for wall assemblies are included in Title 24 as well. The maximum U-factors allowed for walls under the mandatory requirements are:
Walls - metal buildings - 0.113
Walls - metal-framed walls - 0.151
Walls - heavy mass walls - 0.690
Walls - light mass walls - 0.440
Walls - wood-framed walls and other - 0.110
Rmax’s Polyiso Insulation and Title 24
When building in California, using the right products makes achieving compliance a much simpler process. Products like the Rmax Durasheath® building envelope insulation are not only compliant under the California Code of Regulations, but also provide sufficient R-values to satisfy Title 24. Rmax polyiso products are designed as easy to work with rigid foam boards.
Other Rmax products that comply with the California Code of Regulations include:
To learn more about why Rmax polyiso products should be your first choice when building in California, reach out to their team of specialists today!