How to Do a DIY Home Energy Audit

Quick steps

1. Pull 12 months of utility bills. Look for seasonal spikes or unexplained increases, those point to specific problems.
2. Do a room-by-room walkthrough. Attic, walls, windows, doors, HVAC, water heater, and appliances. A flashlight, notepad, and tissue paper (for air leaks) are enough.
3. Rank problems by impact, not ease. Insulation and air sealing typically beat swapping light bulbs. Tackle the biggest heat-loss sources first.
4. Estimate costs and payback. Simple fixes (weatherstripping, outlet gaskets) pay back in months; big ones (insulation, HVAC) in years. Prioritize fastest payback.
5. Plan the top 3 fixes for this season. Don't try to do everything at once; one focused season per area.

What is a home energy audit?

A home energy audit is a room-by-room inspection of how your house uses (and wastes) energy. The goal is to find air leaks, insulation gaps, outdated equipment, and habits that drive up your utility bills. You don't need special equipment for a basic audit. A notepad, a flashlight, and a couple of hours are enough to find the biggest problems. Do one before winter, after a spike in your energy bill, or before planning any major home upgrades.

What you need before you start

• Your last 12 months of utility bills (electric and gas). Look for seasonal patterns and any unexplained increases.
• A flashlight and a notepad, or print the Room-by-Room Energy Audit Checklist from PickShack for a ready-made walkthrough sheet.
• An infrared thermometer ($15-$30) is optional but helpful for spotting cold spots on walls and around windows.
• A stick of incense or a thin piece of tissue paper to detect air drafts around windows, doors, and outlets.

Room-by-room walkthrough

Work through each area systematically. The goal is not to fix everything today, but to identify and rank the problems so you can tackle the highest-impact items first.

• Attic and roof: Check insulation depth (should be at least 10-14 inches of fiberglass or equivalent). Look for gaps around pipes, wires, and the attic hatch. Missing or compressed insulation is the single biggest source of heat loss in most homes.
• Exterior walls: Feel for cold spots with your hand or an infrared thermometer. Check that outlets on exterior walls have foam gaskets behind the cover plates. Older homes often have no wall insulation at all.
• Windows and doors: Hold tissue paper near window edges and door frames. Movement means air is leaking. Check weatherstripping condition, look for cracked caulk, and note any single-pane windows.
• Basement and crawlspace: Inspect rim joists (where the foundation meets the wood framing) for gaps. Check for moisture or condensation. Insulate exposed hot water pipes and any ductwork running through unconditioned space.
• HVAC system: Check the filter (replace if dirty). Note the system age (usually on a label inside the access panel). Listen for unusual noises. Check that all supply and return vents are open and unobstructed.
• Water heater: Check the temperature setting (should be 120F, not the factory 140F). Look for signs of rust or leaking. Note the age. Insulate the tank if it's in an unheated space and more than 5 years old.
• Appliances and lighting: Count how many incandescent or halogen bulbs remain. Check the age and Energy Star rating of your refrigerator, washer, and dryer. Note any electronics left on standby (phantom loads).

How to read your utility bills for clues

• Compare month-to-month usage, not just cost. Rate increases can mask efficiency changes. Look at kWh (electric) and therms or CCF (gas) consumed.
• A spike in winter heating or summer cooling that's larger than the previous year (with similar weather) suggests degrading insulation or HVAC performance.
• If your baseline usage (spring/fall months when neither heating nor cooling runs much) is high, you may have phantom loads, an inefficient water heater, or old appliances driving up costs.
• Many utilities offer online portals that compare your usage to similar homes in your area. If you're consistently above average, there's room to improve.

The 5 highest-ROI energy upgrades

Not all upgrades are equal. These five deliver the most savings per dollar spent, roughly in order of return on investment.

• Air sealing ($50-$200, DIY): Caulk and weatherstrip around windows, doors, outlets, and pipe/wire penetrations. Typical savings: 10-20% on heating and cooling. Payback: under 1 year.
• Attic insulation ($500-$1,500, DIY or pro): Bring attic insulation up to R-38 or R-49 (depending on climate zone). Typical savings: 10-15% on heating. Payback: 2-4 years.
• Programmable or smart thermostat ($25-$250): Set automatic schedules to reduce heating/cooling when you're asleep or away. Typical savings: 8-12% on heating and cooling. Payback: under 1 year.
• LED lighting ($2-$5 per bulb): Replace all remaining incandescent and halogen bulbs. Each LED saves roughly $5-$10/year per bulb. A house with 30 bulbs saves $150-$300/year. Payback: under 6 months.
• HVAC maintenance and tune-up ($80-$150/year): Annual professional maintenance keeps the system running at peak efficiency. A neglected system can lose 5% efficiency per year. Combined with filter changes, this prevents the slow creep of rising energy bills.

When to call a professional

A DIY audit covers the basics, but a professional energy auditor uses tools you don't have: a blower door test (pressurizes the house to measure total air leakage), infrared thermal imaging (reveals hidden insulation gaps and moisture), and duct leakage testing. A professional audit typically costs $200-$500 but many utilities offer them free or at a discount. Always get one before investing in major upgrades like window replacement, new HVAC, or full insulation. The auditor's report will prioritize fixes by ROI, which can save you from spending money in the wrong places.

FAQ

How often should I do an energy audit?

At least once every 3-5 years, or after any major change (new windows, HVAC replacement, additions). A quick check of weather stripping and filters should happen annually before heating season.

What's the difference between an energy audit and a home inspection?

A home inspection evaluates structural condition, safety, and code compliance (typically done when buying a home). An energy audit focuses specifically on efficiency: how much energy the house uses, where it's wasted, and what improvements will save the most money.

Can renters do an energy audit?

Yes. You can identify drafts, replace bulbs with LEDs, add weatherstripping, and use window insulation film. Share findings with your landlord for bigger improvements, especially if your lease includes utilities.

Are energy audit tax credits available?

The Inflation Reduction Act provides tax credits up to 30% for qualifying energy improvements like insulation, heat pumps, and efficient windows (up to $3,200/year). A professional energy audit itself may qualify for a $150 credit. Check dsireusa.org for current federal and state incentives.

Bottom line

Most homes waste 20-30% of their energy through air leaks, poor insulation, and aging equipment. A two-hour DIY walkthrough with a flashlight and a notepad can identify the worst offenders. Start with the cheap fixes (sealing and caulking), work up to insulation, and save window and HVAC replacement for when the numbers justify it.