Most Common Energy Wasters Found During Home Audits

A home energy audit is one of the most effective ways to identify how your home is using—and losing—energy. By spotting the biggest sources of inefficiency, you can make smart upgrades that lead to significant cost savings and a more comfortable living environment. Below are some of the most common energy wasters that professionals uncover during home energy audits.

Poor Insulation

Insulation acts as a thermal barrier that keeps warm air in during the winter and out during the summer. Many homes, especially older ones, have insufficient insulation in areas like attics, walls, and crawlspaces. This lack of insulation forces HVAC systems to work harder, leading to higher energy bills. The U.S. Department of Energy recommends checking your insulation levels and upgrading where necessary to meet modern R-values. Learn more from Energy.gov.

Air Leaks Around Windows and Doors

One of the most common culprits of energy waste is air leakage around windows, doors, and vents. Small gaps or cracks allow outside air to seep in and conditioned air to escape, making heating and cooling systems less effective. Sealing these leaks with weather stripping or caulking is a simple yet highly impactful fix. According to ENERGY STAR®, sealing air leaks can reduce energy costs by up to 20%.

Inefficient HVAC Systems

Heating and cooling systems consume the largest share of energy in most homes. If your HVAC unit is outdated, oversized, or poorly maintained, it may be running inefficiently. During an energy audit, technicians often assess HVAC performance, including airflow, age, and efficiency ratings. Upgrading to a high-efficiency system or scheduling regular maintenance can significantly improve performance and lower utility bills.

Leaky Ductwork

Even if your HVAC system is high-efficiency, leaky ductwork can waste up to 30% of the air it moves. Ducts located in unconditioned spaces like basements or attics are particularly vulnerable. Auditors use pressure tests to detect leaks and often recommend sealing and insulating ducts to prevent energy loss.

Phantom Loads from Electronics and Appliances

Many devices draw power even when turned off—a phenomenon known as phantom load. Items like televisions, chargers, game consoles, and microwaves can silently add to your monthly energy costs. During an audit, homeowners are often surprised by how much energy these devices use. Installing smart power strips or unplugging devices when not in use can reduce this hidden drain.

Old Windows and Single-Pane Glass

Windows plays a major role in a home’s energy performance. Older, single-pane windows offer little insulation and allow for significant heat transfer. Upgrading to double-pane or triple-pane windows with low-emissivity (low-E) coatings can improve thermal performance and indoor comfort. While replacement can be costly, many utility programs offer rebates for energy-efficient window upgrades. Check your eligibility at DSIREUSA.org.

Inefficient Lighting

Switching from traditional incandescent or halogen bulbs to LEDs is one of the easiest energy-saving measures. LEDs use at least 75% less energy and last up to 25 times longer. Many audits reveal that homeowners are still using outdated lighting technologies in key areas. Making the switch to ENERGY STAR®-certified LEDs is a quick win for both the environment and your wallet. Learn more at Energy.gov - Lighting Choices.

Water Heater Inefficiency

Water heating is typically the second-largest energy expense in a home. Outdated or poorly insulated water heaters waste energy and take longer to deliver hot water. Auditors often recommend installing insulation blankets, lowering the temperature setting, or upgrading to a tankless or ENERGY STAR®-rated water heater. For practical advice, visit Energy Saver - Water Heating.

Conclusion

A home energy audit uncovers hidden inefficiencies that could be costing you hundreds each year. From sealing leaks and upgrading insulation to modernizing HVAC systems and replacing outdated lighting, addressing these common energy wasters helps create a more efficient, comfortable, and sustainable home. If you haven’t had an audit yet, consider scheduling one with a certified professional—it’s the first step toward smarter energy use and long-term savings.