Home Energy Audits Explained: What Gets Checked and What It Finds
A home energy audit measures air leaks with a blower door, photographs heat loss with infrared, and ranks the fixes. DOE puts the cost at about $250 to $600. Here is what happens.
By Galactic News Editorial · Published 2026-11-07T19:31:54+00:00 · Updated 2026-11-07T19:31:54+00:00
Home Energy Audits Explained: What Gets Checked and What It Finds
A home energy audit is a structured check of where your house loses energy and money. The U.S. Department of Energy (DOE) calls a proper assessment the essential first step to lowering your energy bills. An assessor measures air leakage, photographs heat loss, and inspects your heating and cooling systems. You get a written report that ranks the fixes. This explainer follows DOE's own Consumer Guide to Home Energy Assessments.
What a home energy audit includes
A professional assessment is an equipment-based look at the whole house. Expect four main elements.
- A walkthrough and bill review. The assessor examines room by room and reviews your recent energy bills to spot usage patterns.
- A blower door test. A powerful fan mounted in a doorway pulls air out of the house. The pressure drop pulls outdoor air in through every unsealed gap. It measures how airtight the house is.
- A thermographic scan. An infrared camera shows warm and cool areas along walls, roofs, windows, and doors. The images reveal missing insulation and the location of air leaks.
- Systems and safety checks. The assessor may inspect heating and cooling equipment, test for natural gas leaks, check ventilation, and use a duct blower to measure leakage inside ductwork.
The two techniques pair up well. When a scan runs during a blower door test, leaks appear as black streaks in the infrared image. A calibrated blower door matters. It connects to a manometer that gives an exact air flow measurement, not just a rough impression.
What it usually finds
Most reports land on the same short list. Air leaks around outlets, window and door frames, attic hatches, and plumbing or wiring penetrations come first. Thin or missing attic insulation is next. Leaky ducts follow, especially where ducts run through attics or garages. Aging heating and cooling equipment rounds out the list. DOE makes the point that some homes need only air sealing and attic insulation. Others justify bigger upgrades, such as replacing heating and cooling equipment. The report should tell you which group your house is in, and in what order to act.
What it costs, and how to prepare
DOE's guide puts a professional home energy assessment at approximately $250 to $600 or more. Many contractors discount the assessment if you hire them for the upgrade work that follows. Help for low-income households exists through DOE's Weatherization Assistance Program, which funds states to weatherize homes.
Preparation is simple, and DOE lists it plainly:
- Write down existing problems first, such as drafty or uncomfortable rooms and condensation.
- Gather copies or summaries of recent energy bills for the assessor.
- Be ready to describe daily usage patterns, room by room.
- Use a certified assessor. DOE suggests asking your utility, your state energy office, or an ENERGY STAR program listing.
You can also do a basic version yourself. DOE's guide describes a DIY walkthrough using a smoke stick or incense near likely leak points on a cool, windy day. It will not match a blower door measurement. It costs nothing and still finds the worst drafts.
Bottom line
A home energy audit turns guesswork into a ranked list. The blower door test finds and measures the leaks. The infrared scan shows where heat escapes. The report then separates cheap fixes, like sealing and insulation, from major purchases. At roughly $250 to $600 by DOE's figures, it is the cheapest way to avoid spending thousands on the wrong upgrade first.