DOE Determination of the 2024 IECC Energy Cost Savings
We applaud the Department of Energy (DOE) for meeting its statutory obligation to publish a determination of whether the most recently published residential energy code, the 2024 International Energy Conservation Code (IECC), improves energy efficiency as compared to the previous version. State and local jurisdictions rely on these determinations to guide their code adoption processes in a manner that benefit homeowners in terms of higher quality homes and lower energy bills.
While we recognize that the 2024 IECC determination shows a total energy cost savings of 6.6%, the 2024 IECC was published with weakened efficiency measures compared to the 2021 IECC that jeopardize the long-term benefits to homeowners. The 2024 IECC measures that result in greater energy burdens to homeowners include:
Weakened ceiling insulation R-values in nearly every region of the country resulting in a less efficient thermal envelope.
An allowance to trade away the long-term benefits of thermal building envelope wall insulation for one of several measures that reward homebuilders for installing specific types of equipment (heat pumps, heat pump water heaters, renewable energy systems) and leave homeowners with higher home cooling and heating loads.
Additional equipment trade-offs when using the simulated building performance compliance option that are based on outdated assumptions resulting in the installation of HVAC equipment that do not provide homeowners with any meaningful improvement in home energy efficiency.
Weakened energy efficiency measures that negatively impact the performance of building thermal envelopes moves the home construction industry in the wrong direction. We know that efficient envelopes are vitally important for the following reasons:
Lower utility bills – resulting in lower ownership costs and greater affordability.
Energy security – lowering our dependence on foreign fuel sources and the nations that control them.
Resilience, health and safety – energy efficient homes and buildings provide increase protection against indoor air contaminants, moisture that can cause mold inside walls, heat and cold even when there is a loss of power, and more.
Faster transition to clean energy sources – reducing our energy needs allows us to build fewer or smaller energy generation plants and easing the costs to build new or transition old plants.
Reduced renewable energy and HVAC system sizing – lowering the energy demand of a home or building can reduce the size of the heating and cooling equipment or renewable energy system. This reduces the costs of these systems making them more affordable.
Carbon emissions reductions – when we use less energy we reduce carbon emissions. Even if our energy source is clean there is still carbon associated with the energy system, transmission and use of the energy.
Comfort – people who live and work in energy efficient homes and buildings report being more comfortable due to more consistent temperatures and fewer drafts.
As a representative of EECC, I look forward to serving as residential committee member for the development of the 2027 IECC which we hope will result in efficiency improvements that benefit consumers. We also hope that the weakened provisions of the 2024 IECC will be restored wherever it is adopted to prevent energy from being wasted and homeowners from being robbed of important benefits.
Amy Schmidt
Executive Director
Energy Efficient Codes Coalition