A home energy audit identifies where your house wastes energy—air leaks, poor insulation, inefficient appliances, and more. Whether you do it yourself or hire a professional, the results guide targeted improvements that can cut your electricity bill by 20–30% or more.
What Is a Home Energy Audit?
An energy audit systematically evaluates your home's energy use. It examines the building envelope (walls, roof, windows, doors), HVAC systems, lighting, appliances, and occupant behavior. The goal is to create a prioritized list of improvements with estimated costs and savings.
DIY Energy Audit: Step-by-Step
1. Review Your Bills
Gather 12–24 months of electricity and gas bills. Note seasonal patterns and compare to similar homes (many utilities provide this). High usage relative to square footage or family size suggests significant waste.
2. Check for Air Leaks
On a windy day, walk through your home feeling for drafts. Use an incense stick or thin tissue—movement indicates airflow. Focus on windows, doors, electrical outlets on exterior walls, baseboards, attic hatches, and where pipes or wires enter the building.
3. Inspect Insulation
In the attic, check insulation depth and condition. Recommended R-values vary by climate (R-38 to R-60 for attics in most regions). Look for gaps, compression, or moisture damage. Ensure insulation doesn't block soffit vents.
4. Evaluate HVAC
Check filter condition and replace if dirty. Inspect ductwork in attics and crawl spaces for leaks, disconnections, or inadequate insulation. Ensure vents are not blocked by furniture or rugs.
5. Assess Lighting and Appliances
Count incandescent bulbs and note their locations. List major appliances and their age—older units are often less efficient. Check for phantom power (devices with indicator lights or warm adapters when "off").
6. Examine Water Heating
Note the water heater type, age, and location. If it's in an unheated space, consider an insulating blanket. Check for leaks and set temperature to 120°F (49°C) unless you need higher for a dishwasher without a booster.
- Document findings with photos and notes
- Prioritize by impact and cost (quick wins first)
- Create an action plan with timelines
When to Hire a Professional
Consider a professional audit if you have an older home, suspect hidden issues, plan major renovations, or want the most accurate assessment. Professionals use:
- Blower door test: Depressurizes the home to measure total air leakage and locate leaks
- Thermal imaging: Identifies heat loss, moisture, and insulation gaps
- Combustion safety testing: Ensures gas appliances vent properly
- Detailed report: Prioritized recommendations with cost and payback estimates
Cost of Professional Audits
Basic audits run $100–300. Comprehensive audits with blower door and thermal imaging cost $300–600 or more. Many utilities offer discounted or free audits. Some states have programs that cover part or all of the cost for income-qualified homeowners.
"I did a DIY audit first and fixed the obvious issues. Then I hired a professional before a major renovation. The thermal imaging found insulation gaps we never would have located ourselves. Worth every penny."
Acting on Audit Results
Start with low-cost, high-impact items: sealing air leaks, adding insulation where needed, replacing filters, and upgrading lighting. Move to larger investments—HVAC replacement, window upgrades—based on payback and budget. Use ElectriBill's calculator to model savings as you implement changes.
How Often to Audit
Conduct a basic DIY audit annually. Schedule a professional audit every 5–10 years, or when you're planning major changes, buying a home, or experiencing unexplained high bills.
An energy audit is one of the best investments you can make in your home. The insights it provides pay dividends for years through lower bills and improved comfort.