Accessory Dwelling Units, or ADUs, are becoming an increasingly popular way to add living space and housing options to existing residential properties. In California, ADUs are subject to a number of regulations and requirements, including Title 24 of the California Code of Regulations. Title 24 sets standards for energy efficiency, lighting, and other aspects of building design and construction. In this blog post, we will explore California's Title 24 requirements for ADUs and explain what homeowners and builders need to know to ensure compliance.

Promoting Energy Efficiency

One of the main purposes of Title 24 is to promote energy efficiency and reduce the environmental impact of buildings. California has set ambitious goals for reducing greenhouse gas emissions and promoting sustainable building practices, and Title 24 is a key tool in achieving these goals. The regulations apply to all new construction and remodeling projects in the state, including new construction ADUs.

Insulation, Systems, and Construction Considerations

For ADUs, Title 24 requires compliance with specific energy efficiency standards. This includes requirements for insulation, air sealing, heating and cooling systems, and more. For example, ADUs must have insulation that meets minimum R-value requirements, and they must be designed to minimize air leakage. HVAC systems must also meet certain efficiency standards to reduce energy consumption and emissions. We typically recommend that ADUs have insulated wall cavities in addition to continuous rigid insulation around the entire outside of the home. We also recommend ductless mini-split systems as an efficient way to provide heating and cooling.

Lighting Considerations

In addition to energy efficiency requirements, Title 24 also sets standards for lighting in ADUs. These requirements are designed to promote energy efficiency and ensure that ADUs are well-lit and safe for occupants. This includes requirements for the type and placement of light fixtures, as well as the use of lighting controls such as timers and motion sensors. To meet lighting requirements and reduce energy consumption we recommend LED light fixtures throughout all ADU projects.

Accessible Design

Another important aspect of Title 24 for ADUs is the requirement for accessible design. California law requires that all new construction and remodels meet accessibility standards under the Americans with Disabilities Act (ADA). This includes ADUs, which must be designed to be accessible for individuals with disabilities. This may include features such as wider doorways, lower countertops, and accessible bathroom facilities.

Solar Energy Requirements

An important aspect of Title 24 is the requirement to add solar energy systems that will offset the energy use of new construction residential projects. This includes ADUs. It is important to consider this requirement when budgeting for your project as well as locating the ADU on your property. Making sure the roof pitch is best oriented towards the sun will help you get the maximum benefits of a PV system. Along with solar energy production, you could also consider solar hot water systems and a way to further reduce your energy consumption and make your ADU more sustainable.

How To Comply

Most jurisdictions in California require a Title 24 report that analyzes your ADU design and does that calculations to show it complies with the code requirements. There are many companies that can provide these reports in only a few days time and typically for a few hundred dollars. They will provide the documentation and/or drawings needed to submit to your building department as part of the permit review process.

Overall, California's Title 24 requirements for ADUs are designed to promote energy efficiency, safety, and accessibility. While complying with these requirements can add some additional costs to a project, it is important to ensure that ADUs are built to the highest standards of quality and sustainability. By following these requirements, homeowners and builders can create ADUs that are comfortable, safe, and environmentally friendly, and that will provide long-lasting benefits for years to come.

Typically Title 24 reports are performed once the design of the ADU is completed but prior to submitting to permit. You can use our pre-designed ADU drawing sets to send to a company that provides Title 24 Reports and typically you can get the report in a few days.

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