How to Perform a DIY Energy Audit

A row of dark houses with one glowing yellow.

Electricity bills giving you heart palpitations? You’re not alone—many homeowners experience a sharp spike in energy spending throughout the summer and winter. But if your rates seem sky-high, it’s possible that your home’s experiencing some energy loss that can drive up electricity and fuel expenses.

If you think your bills are off, a DIY home energy audit is a solid first step to root out common inefficiencies. Professional audits are more thorough, of course—the pros have advanced tools at their disposal, like blower door tests and infrared cameras—but they’ll also run you around $400. These tips will give you a good place to start, especially if you’re trying to save money. The U.S. Department of Energy estimates that an audit could potentially reduce your energy costs by as much as 30 percent, so that’s a pretty good return for an afternoon spent with a ladder and a flashlight.

Furthermore, performing these kinds of tests yourself helps you understand how your home uses energy—and where to look for problems in the future. Here are some areas to assess, and how to tell if there’s an issue.

Windows and Doors

A man putting caulking on a window sill.

In homes with old or leaky windows and doors, a potential 10 to 20 percent of your home heating could be going right out the window. Your home’s windows and doors should be the first place you check for leaks, since they’re both easy to spot and repair.

Test for Drafts

Drafts are a key sign that there’s poor air sealing, so finding the gaps and cracks where air enters is of the utmost importance in a home energy audit. There’s one homegrown test that can help you out here: take an incense stick or candle and carry it from room to room around your home, holding it near each window and exterior door. If the flame or smoke flickers, you may have just found a leak. For even more accurate results, wait until the weather is windy or breezy, so the effect is all the more visible.

Inspect Window Sealing

To further assess your home’s air sealing, visually inspect the window frames—particularly on your home’s exterior—where the frame attaches to the siding. If the sealant is cracked, scrape out the existing caulk and apply in its place a layer of silicone in a smooth bead. And if you haven’t already installed weatherstripping to your home’s windows, now’s as good a time as ever! Attach foam stripping to the moving parts of the window, and place a rubber flap across the bottom of the lower sash.

Check Your Doors

Have a look around each exterior door and verify that no cracks have formed, and that the weatherstripping is still intact. If you don’t already have one, attach a vinyl sweep seal to the bottom of the door to prevent air from seeping there.


An electrical outlet without a plate over it.

While it’s difficult for an amateur inspector to verify all your home’s electrical components, there are a few common problem areas you should keep an eye out for.

Have a Look at Recessed Lights

Recessed lights are commonly vented directly to attics, and may be installed without insulation, so they’re a frequent source of heat loss. Check that your lights have an "Air Loc" rating—this means they’re designed to reduce air flow.

Check Outlet Plates

They may seem small, but uninsulated outlet plates and light switches can siphon off a lot of your home’s energy. Remove each plate one by one and verify that they all have a foam gasket installed beneath.

Switch to LEDs

If you haven’t already, replace incandescent bulbs with CFLs or LEDs, which last longer and throw off significantly less heat than traditional incandescents.


A ruler measuring pink insulation.

Insulation is another part of the home that’s difficult to inspect without the help of a professional auditor, since most of it is buried inside your home’s walls. However, there are a few tests you can perform before you call the pros.

Measure Insulation Thickness

Although the majority of your home’s insulation lies inside the wall cavities, you may have exposed insulation in your attic, basement, or around your home’s ducts. In these places, measure its thickness with a ruler. Then use an insulation calculator to see how it stacks up against recommendations for your area.

Look for Discoloration

While you’re at it, visually inspect the insulation in these spots to see if there are stains or discoloration, as that might indicate that a crack or duct leak is hiding below the surface. If you spot an issue here, your next step should be to contact a contractor to offer their professional opinion.

Inspect Insulation in the Attic

Many attics aren’t heated, so air loss can occur here through cracks in the ceiling, or if the insulation in the attic floor is poor. First, look for gaps or openings in the attic floor—if the gap is very large, you’ll be able to see the light shining through from the floor below. As you inspect, you should also be on the lookout for discoloration on the insulation, a sure sign of hairline cracks below.

Ductwork and HVAC

A dented piece of ductwork.

Damaged ducts and clogged registers also prevent your home’s HVAC from working as smoothly as it should, and that causes heating and cooling bills to rise. To catch these issues, have a look at the following:

Inspect Ductwork

Probe your home’s ductwork with a flashlight, looking for damaged, tangled, or kinked pieces. Additionally, view the seals at the registers and grills—they should be tight enough to keep your HVAC from leaking. Seal any problem areas with metal tape or mastic sealant.

Cut Back Brush Around the Exterior Unit

If the outside AC unit in your home is overgrown with brush, it can hinder its performance. Cut back any overgrowth and visually inspect the unit to make sure there are no leaves or twigs clogging it.

Vacuum Registers

Dust and buildup commonly form around HVAC registers over time, which can make it harder for your system to circulate heated or cooled air. To clean them, remove the cover and take a vacuum to the interior. Push the hose deep into the entrance to clear out as much buildup as possible.

A home inspection may take a little bit of work, but it’s nothing the average homeowner can’t handle with a little elbow grease. And with hundreds of dollars on the line, it’s definitely worth the trouble!

About the Writer

Erin Vaughan is a blogger, gardener, and aspiring homeowner. She currently resides in Austin, TX where she writes full time for, with the goal of empowering homeowners with the expert guidance and educational tools they need to take on big home projects with confidence.