Navigating Title 24 ADU requirements can be a nightmare, so we decided to create this guide to simplify the whole process.
We’ll not only cover exactly what Title 24 is and how it relates to the ADU construction process, but we’ll also share specific examples and how you can achieve compliance in the most straightforward way.
What Is Title 24 in California?
Title 24 refers to California’s Building Energy Efficiency Standards.
These regulations, originally introduced in 1978, are designed to reduce energy consumption in new and existing buildings.
Title 24 impacts all aspects of building design and construction, ensuring structures, including ADUs, are energy-efficient.
The standards cover everything from insulation and windows to lighting and appliances, all aimed at reducing greenhouse gas emissions and promoting sustainability.
Compliance with Title 24 is mandatory for any new construction or major renovation in California.
Does an ADU Even Need Title 24?
Yes, ADUs must comply with Title 24 regulations.
Whether you’re building a new ADU or converting an existing structure, you need to meet the energy efficiency standards set by Title 24.
Energy-efficient ADUs save on utility bills, maintain comfortable indoor temperatures, and reduce the overall carbon footprint. Failing to comply can result in delays in permitting and additional costs.
Working with an Expert
Working with an experienced ADU builder or energy consultant is highly recommended, and can save you a lot of headaches and time.
These professionals understand the detailed requirements and can guide you through the process, ensuring compliance while optimizing your ADU’s energy efficiency.
They can also help you choose between the Performance and Prescriptive methods (more on this shortly), select the right materials, and complete the necessary documentation, saving you time, money, and headaches.
How To Achieve Title 24 Compliance – Two Approaches
There are two popular approaches for achieving Title 24 compliance on an ADU build project.
Performance Method
The Performance Method offers flexibility by allowing you to meet overall energy efficiency targets using energy modeling.
This approach lets you make trade-offs; for example, you can install higher-efficiency windows if your insulation is slightly below standard. Energy modeling software is used to simulate the ADU’s energy use, and if the model meets or exceeds Title 24’s requirements, the design passes.
This method is ideal for customized ADUs where specific design elements need flexibility.
Prescriptive Method
The Prescriptive Method is more straightforward but less flexible.
It involves following a predefined set of measures that meet Title 24 standards. These measures include specific insulation levels, window types, HVAC systems, and lighting controls. Each component of the building must meet or exceed the minimum requirements without trade-offs.
While this method is easier to implement, it may be less adaptable to unique designs or specific site conditions. It’s best suited for standard ADU designs where customization is minimal.
Examples of Title 24 Requirements for ADUs
It’s much easier to understand Title 24 requirements for ADUs by looking at some specific examples and how they would play out in real life.
Water Heater (Electric Heat Pump)
Title 24 often requires the installation of an electric heat pump water heater, which is more energy-efficient than traditional gas models.
Heat pump water heaters use electricity to transfer heat rather than generate it, significantly reducing energy consumption and lowering greenhouse gas emissions.
Solar Energy
Under Title 24, all new residential buildings, including ADUs, must include solar photovoltaic systems.
The actual size varies from ADU to ADU, but the goal is for the solar system to offset the total energy usage of the ADU itself, aligning with California’s goal of achieving net-zero energy buildings.
Insulation
‘Proper’ insulation is a cornerstone of Title 24 compliance.
The standards specify the required R-value for walls, roofs, and floors, which measures the material’s resistance to heat flow.
To keep it simple, the higher the R-value, the greater the energy efficiency of the insulation – so in this case, minimum R values are set which must be met.
Fans
Yep, even fans are included.
Ventilation fans in ADUs must meet specific energy efficiency standards, with limits on the power and airflow of fans to ensure they are energy efficient.
Kitchen Hood Field Test
Title 24 requires a field test for kitchen hoods to ensure they effectively remove cooking pollutants while maintaining energy efficiency.
HERS Testing
Home Energy Rating System (HERS) testing is a critical component of Title 24 compliance.
HERS testing is simply when all of the energy-efficient features of your ADU get tested to see if they’re up to scratch.
A third party conducts these tests, and they will focus on things like insulation, duct sealing, HVAC performance, and more.
The Big Picture
Achieving Title 24 compliance for your ADU is not just about meeting legal requirements—it’s about building a sustainable, energy-efficient home that benefits both the environment and your wallet.
Whether you choose the Performance or Prescriptive Method, hiring an expert to guide you through the process will make everything much easier.