Compared to their standard/gas home counterparts, LZE homes will require unique considerations throughout their construction and operation. Builders incorporating these components for the first time will need to make new financing and marketing considerations, as well as adopt new technical approaches.
Using the low and zero emission homes created by Ivory Homes, Sego Homes, and Garbett Homes as examples, the following information can help empower builders with the knowledge they need to feel comfortable entering the energy-efficient building space.
Technical Approach
Both the ENERGY STAR NextGen and Zero Energy Ready Home standards go above what is required by Utahās building code, the 2021 IECC building code, and ENERGY STAR v3.2. As shown in the first table below, the ENERGY STAR NextGen and Zero Energy Ready Home programs require advanced HVAC and water heating equipment, EV- and/or PV-readiness, and adherence to 2021 IECC building envelope requirements. The tables below show building envelope requirements by component, dependent on Utah’s three climate zones.
A comparison of home building standards by their components and associated efficiency/equipment requirements. Based on Utah climate zone requirements and sourced from Resource Innovations (2024).
Builders can reference the tables below to determine building component standards for their low and zero emission homes. For more detailed information, reference:
- 2021 IECC Building Envelope UA Requirements
- ENERGY STAR NextGen Program Requirements
- Zero Energy Ready Home Program Requirements
Builders have some flexibility in how they choose to achieve ENERGY STAR NextGen or Zero Energy Ready Home program targets. For instance, builders can use higher efficiency HVAC or improved air sealing to compensate for lower R-values in some areas ā as long as they achieve the overall air tightness and/or Energy Rating Index scores required by the program. The below table illustrates this flexibility, showing equipment and efficiency data by component for each of the three showcase home builders.
In the early stages of planning for LZE home construction, builders should contact their contractors and suppliers to set expectations for the equipment and materials their home will require. In the design phase, energy modeling software can help builders plan for and maximize energy-efficient performance. During construction (after building envelope components are installed), blower door testing is required to prove adherence to airtightness targets. After construction, securing a Home Energy Rating System (HERS) report for the home demonstrates compliance to low and zero emission standards and provides data regarding the homeās estimated annual energy usage, utility cost savings, and more.
Common Challenges and Resolutions
The builders who participated in the Low and Zero Emission Housing Initiative ā both those building and modifying home plans to meet ENERGY STAR NextGen or Zero Energy Ready Home certification requirements ā each experienced unique challenges as they tackled LZE building and design. The following list summarizes some of these encountered challenges and how the builder addressed them/lessons other builders can take from those challenges:
We would like to clarify thatĀ Utah Clean EnergyĀ isĀ not a solar company. We are a nonprofit organization that advocates for solar and other clean energy technologies, but we do not install or sell solar in any way.