Home Energy Audit Guide 2026: Find and Fix Energy Waste

Updated March 2, 2026 · 12 min read · by 13.energy

The average American household spends $2,000-$3,000 per year on energy. A thorough energy audit identifies where that money goes and which improvements offer the highest return. Most homes can reduce energy costs by 20-30% through improvements identified in an audit — that is $400-$900 in annual savings.

DIY Energy Audit Checklist

Air Leaks (Biggest Energy Waste)

Air leaks account for 25-40% of heating and cooling costs in most homes. Check these common leak points:

• Windows and doors: Hold a lit incense stick near window frames and door edges. Smoke movement indicates a leak. Weatherstripping costs $5-$10 per door and saves $50-$100 annually per sealed door
• Electrical outlets and switches: On exterior walls, remove the cover plate and feel for air movement. Foam gaskets ($0.50 each) seal these gaps
• Attic access: The attic door or pull-down stairs are often the largest air leak in the house. Weatherstrip and insulate the attic access point
• Plumbing and wiring penetrations: Every hole where pipes or wires enter the house is a potential leak. Seal with caulk or expanding foam
• Recessed lighting: Non-IC-rated recessed lights leak tremendous amounts of conditioned air into the attic. Replace with IC-rated LED fixtures or cover with insulated boxes

Insulation

Location	Recommended R-Value	Check For
Attic	R-38 to R-60	Measure depth: fiberglass needs 10-14 inches
Walls	R-13 to R-21	Hard to check; infrared camera reveals gaps
Basement/crawlspace	R-10 to R-19	Exposed fiberglass should face heated space
Ductwork	R-6 to R-8	Ducts in unconditioned spaces need insulation

HVAC System

• Filter check: A dirty filter reduces efficiency by 5-15%. Replace every 1-3 months during heavy use seasons
• Age assessment: Systems over 15 years old are significantly less efficient than modern units. A new ENERGY STAR system can reduce heating and cooling costs by 20-40%
• Duct inspection: Leaky ducts waste 20-30% of conditioned air. Feel for air leaks at duct joints in unconditioned spaces. Seal with mastic or metal tape (not duct tape, which deteriorates)
• Thermostat programming: A programmable or smart thermostat saves 10-15% on heating and cooling by reducing output when you are away or sleeping

Appliances and Lighting

• Identify energy hogs: Use a Kill-A-Watt meter ($25) to measure individual appliance consumption. Old refrigerators, dehumidifiers, and space heaters are common offenders
• Lighting audit: Replace remaining incandescent and CFL bulbs with LED. Each LED bulb saves $3-$8 per year. A typical home has 30-40 bulbs — that is $90-$320 in annual savings from LEDs alone
• Phantom loads: Devices that draw power while off (TVs, game consoles, chargers) cost $100-$200 annually. Use smart power strips to cut phantom loads

Professional Energy Audit

A professional audit costs $200-$500 and provides significantly more detail than DIY:

• Blower door test: Depressurizes the house to measure total air leakage and locate specific leak points
• Infrared camera scan: Reveals insulation gaps, moisture problems, and air leaks invisible to the naked eye
• Duct leakage test: Pressurizes the duct system to measure exactly how much conditioned air is lost
• Combustion safety testing: Ensures gas appliances vent properly and do not create carbon monoxide risks

Many utility companies offer free or subsidized professional audits. Check with your local provider — ComEd, Peoples Gas, and Nicor Gas all offer programs in the Chicago area.

Top Energy Improvements by ROI

Improvement	Cost	Annual Savings	Payback Period
Air sealing (caulk, weatherstrip)	$50-$200	$100-$300	3-12 months
LED lighting upgrade	$50-$150	$90-$320	3-12 months
Smart thermostat	$150-$300	$150-$300	6-24 months
Attic insulation	$1,500-$3,000	$200-$500	3-6 years
HVAC upgrade	$5,000-$12,000	$400-$1,000	5-12 years

Frequently Asked Questions