Understanding HERS Testing and Title 24 Compliance in California
As California leads the way in energy efficiency, Title 24 remains a key part of the state’s building standards. It sets strict guidelines to reduce energy use in both residential and commercial buildings.
A critical component of Title 24 is the HERS rating (Home Energy Rating System). This index measures how efficiently a building uses energy and helps verify that construction meets required standards.
In this article, we’ll explain the importance of HERS testing for Title 24 compliance, and how it benefits builders, homeowners, and the environment.
What is a HERS Rating?
A HERS rating is a quantified assessment, given as a numerical value, that signifies the energy efficiency level of a building. The more energy-efficient a building is, the lower its HERS rating will be. The HERS test evaluates multiple aspects including wall insulation that complies with Title 24, windows that meet Title 24 specifications, climate zone-appropriate HVAC systems, residential lighting, and energy-efficient appliances. In this scoring system, a HERS rating of 100 serves as the benchmark, symbolizing a standard reference home, whereas a HERS score of 0 signifies a home that achieves zero-energy consumption.
Do I Need a HERS Raters for single family building ?
For single-family building ( SFR), you’ll need a HERS Rater when the Certificate of Compliance (CF1R) indicates the necessity of HERS evaluations.
For New Builds, Larger Additions, and Accessory Dwelling Units (ADUs): Specifically, for new constructions, and additions exceeding 1,000 square feet, and all sizes of ADUs, there’s always a requirement for a minimum of one HERS evaluation. This is particularly for verifying ventilation airflow. However, other verifications might be needed based on the specific installations in the property.
For Smaller Additions and Home Alterations: For projects with additions less than or equal to 1,000 square feet and any modifications to an existing residence, the necessity for HERS evaluations is influenced by the features introduced. You’ll find the HERS measures that are mandated listed on the Certificate of Compliance (CF1R).
Why is HERS required for compliance with Title 24?
California’s Title 24 mandates a minimal degree of energy efficiency for all new constructions, gauged by the HERS index. HERS Ratings act as the state’s mechanism to verify if newly erected buildings conform to targeted energy performance criteria, thereby minimizing energy use and reducing greenhouse gas emissions.
Builders can leverage a low HERS Rating as a unique selling point, setting their constructions apart in the marketplace. Not only does this offer a competitive advantage, but it also assists builders in adhering to Title 24 California norms, averting potential legal repercussions and project delays.
For homeowners, a house with a low HERS rating translates into reduced energy bills and a more comfortable living space. Such energy-efficient homes are not only less expensive to run but also represent a wise long-term investment.
The Building Envelope as a Title 24 and HERS Consideration
In the grand scheme, the building envelope serves as a pivotal factor in meeting Title 24 requirements. Proper insulation techniques such as radiant barrier installation, meticulous air sealing, and the implementation of Title 24-compliant windows are all integral in curtailing energy loss and elevating a building’s overall energy efficiency. Utilizing electric tankless hot water heaters or electric on-demand water heaters can also contribute to a more favorable HERS Rating.
Comprehensive List of HERS Tests
The tests and verifications performed can vary depending on the nature of the residential project. The following are the key assessments that may be required:
Title 24 Requirement for Ductwork
Duct Sealing
A duct leakage test is required to ensure the system does not exceed the maximum allowed leakage rate. The leakage limit varies depending on whether it’s a new construction or an alteration. Inspectors must also verify that approved sealing materials are used.
Return Duct Design & Air Filter Devices
A visual inspection checks that the return duct system follows Title 24 design standards. Inspectors also ensure air filter devices meet efficiency and accessibility requirements.
This inspection can be used as an alternative to the Cooling System Airflow and Fan Efficacy test.
Bypass Ducts (Zonally Controlled Systems)
For zoned central forced-air units (FAUs), bypass ducts are generally not allowed.
A visual check confirms compliance. If bypass ducts are used, a performance penalty is applied under the Title 24 energy model.
Low Leakage Ducts in Conditioned Space
When all ducts are located entirely within conditioned space, a visual inspection confirms placement and design. Testing must also verify that leakage levels stay within Title 24 limits.
Duct Design (Including Buried and Deeply Buried Ducts)
Inspectors check that the duct system is installed as designed, including:
Correct location and size
Approved duct insulation (R-value)
Proper duct lengths and layout
Sealing and insulation must meet Title 24 requirements for efficiency and performance.
Title 24 HVAC Systems
- Air Handlers with Low Leakage: Confirm that the air handlers are sealed properly.
- Refrigerant Level in Ducted and Mini-Split AC and Heat Pump Systems: Check that the refrigerant charge is optimal.
- Fan Efficiency in Air Handlers: Verifying that the fans in the air handlers are operating efficiently.
Ventilation and Airflow
- Continuous Whole-Home Mechanical Ventilation Airflow: Ensuring that the ventilation system provides a continuous airflow.
- Intermittent Whole-Home Mechanical Ventilation Airflow: Confirming intermittent airflow in the ventilation systems.
Insulation and Building Envelope
- High-Quality Insulation Installation: Checking the quality of insulation installed.
- Building Shell Air Tightness: Assessing how well the building’s envelope is sealed against air leakage.
Hot Water Systems
- Verified Pipe Insulation Credit: Verifying the quality of pipe insulation.
- Compact Hot Water Distribution System Verification: Ensuring the efficiency of hot water distribution.
Others
- Solar Panel Verification Protocol: Checking the installation and efficiency of solar panels.
- Design of Multiple Recirculation Loops for Domestic Hot Water Systems in Multi-Unit Buildings: Inspecting the design of hot water systems in multi-unit residential buildings.
In summary, HERS Rating is an invaluable tool for ensuring new structures in California satisfy Title 24’s energy-efficiency prerequisites. This harmonizes with the interests of builders, property owners, and the broader environment by paving the way towards a more sustainable future. If you’re embarking on a new construction project or contemplating a remodel, it would be prudent to collaborate with a qualified HERS Rater to confirm Title 24 compliance and optimize your structure’s energy capabilities.