Extreme heat is impacting most of the United States – an occurrence that is only expected to become more common. There are simple solutions that state and local governments can get behind right now to help keep homes comfortable during the summer months.
Here are three policy ideas to beat the heat.
Promote Unvented Attics
An unvented attic is created by using air impermeable insulation, like spray foam insulation, on the underside of the roof deck to seal the attic, bringing it and any ductwork or heating, ventilating, and air conditioning (HVAC) systems inside “conditioned space.” On a typical summer day, a traditional vented attic can hit 120 degrees. An unvented attic would be only a few degrees warmer than the setting on a thermostat.
This provides a more hospitable environment for HVAC mechanical equipment and duct work. Additionally, any duct leakage is now inside the thermal envelope, further reducing energy losses.
Installing an unvented attic is like putting a hat on your house. It keeps the entire structure cooler in the summer and warmer in the winter. It also allows your HVAC system to operate in a milder climate – further increasing energy efficiency.
More information about the benefits of unvented attics can be found here.
State and local governments should promote the use of unvented attics in new construction and retrofit as solution to maximize energy efficiency.
Adopt New Codes which Enforce Air Sealing
Modern energy codes prioritize construction of more efficient building envelopes. The best performing building envelopes are well insulated and air sealed.
A home’s HVAC system has a big effect on energy consumption. The U.S. Energy Information Agency estimates that 51% of the energy consumed by homes is used for heating and cooling.[1] Compounding the issue is that up to 40% of the energy used to heat and cool a home is wasted due to air leaks.[2]
Installing a continuous air barrier to seal the building envelope helps ensure energy efficiency. Gaps, holes, and air leaks can make energy bills unnecessarily high and let valuable resources (i.e. conditioned air) go to waste. The potential energy savings from air sealing a home can be as high as 30% per year.[3]
Limiting air leakage with a continuous air barrier is generally accepted as good building science; in fact, the International Energy Conservation Code (IECC) first implemented requirements to limit air leakage in 2009 – with the testing requirement taking effect in 2012.
Additionally, the Energy Star program (run jointly by the U.S. Department of Energy and the U.S. Environmental Protection Agency) promotes the benefits of air sealing the building envelope.[4] Sealing homes with spray foam insulation can help create a comfortable, clean, fresh-feeling home. The closure of air leaks and gaps manages moisture and humidity, as well as pollen, which can help protect occupants during allergy season.
State and local governments should adopt new building codes and implement air tightness requirements to make homes more comfortable and energy efficient.
Incentivize Energy Efficiency Retrofits
Most homes in the United States were built before modern energy codes were introduced, and as a result, are under-insulated and lack a quality air barrier. There are many options to retrofit homes to improve comfort and energy efficiency.
In 2022, the Environmental Protection Agency (EPA) estimated that retrofitting homes, built before energy-saving insulation standards were required, could cut energy use in half.[5] Moreover, the Department of Energy (DOE) estimated that for every dollar spend on retrofitting or weatherization, homeowners could see a $2.78 return in savings.[6]
While retrofitting all aspects of the home is important, climate economist Gernot Wagner emphasizes that proper insulation is necessary to realize benefits of home retrofits.[7]
State and local governments should develop tax credits or incentive programs to aid in the retrofit of existing buildings.
[1] https://www.energy.gov/eere/why-energy-efficiency-upgrades
[2] https://www.energystar.gov/campaign/seal_insulate/why_seal_and_insulate
[3] https://www.fastcompany.com/90759402/why-biden-just-used-one-of-his-most-significant-powers-on-insulation
[4] https://www.popsci.com/environment/energy-justice-explained/
[5] https://news.bloomberglaw.com/environment-and-energy/home-insulation-tax-credits-need-a-push-from-biden-groups-urge