Home Energy Audit: What It Is and Why You Need One

What Is a Home Energy Audit?

A home energy audit is a professional assessment that identifies where and how your home wastes energy. Using specialized tools — blower doors, thermal cameras, combustion analyzers — an auditor measures actual performance rather than guessing.

The result is a prioritized list of upgrades, each with estimated cost and expected savings. It’s the difference between blindly replacing windows and knowing exactly where your dollars are leaking out.

Who Should Get One?

Consider an energy audit if you:

• Have high utility bills relative to similar homes
• Notice cold drafts, hot spots, or uneven temperatures
• Plan major renovations or an HVAC replacement
• Just bought an older home
• Want to qualify for utility rebates or tax credits
• Suspect moisture, mold, or indoor air quality issues

Most homes built before 2010 benefit, and homes built before 1990 almost always do.

What Happens During an Audit

A typical audit takes 2 to 4 hours.

1. Homeowner Interview

The auditor asks about comfort complaints, bill history, equipment age, and renovation history. This narrows the focus to what actually bothers you.

2. Visual Inspection

Walk-through of the attic, basement, crawl space, living areas, and mechanical rooms. The auditor notes insulation levels, air barriers, HVAC condition, appliance age, and lighting.

3. Blower Door Test

A powerful fan is mounted to your front door and depressurizes the home to 50 Pascals (roughly a 20 mph wind on all sides at once). This quantifies air leakage in air changes per hour (ACH) and lets the auditor find leaks you can’t feel.

A result of 7+ ACH means your home is leaky. Under 3 is tight.

4. Thermal Imaging

Infrared cameras reveal where heat is escaping (winter) or entering (summer). Missing insulation, air leaks, and wet spots show up as cold or hot patches.

5. Combustion Safety Test

For homes with gas appliances, the auditor checks for:

• Carbon monoxide leaks
• Proper draft on water heaters and furnaces
• Gas leaks at connection points
• Adequate combustion air

This is a safety issue, not just efficiency.

6. Duct Testing (if requested)

A duct blaster test measures how much conditioned air your ducts leak into unconditioned spaces. Typical homes lose 20 to 30% — a shocking amount of money vanishing into attics and crawl spaces.

7. Report and Recommendations

Within a few days, you receive a written report with:

• Current performance metrics
• Specific improvements ranked by ROI
• Estimated costs and savings for each
• Rebate and tax credit information

Typical Costs

A standard home energy audit costs $150 to $600, with most falling around $300 to $500. Costs vary by:

• Home size
• Scope (includes duct testing? combustion analysis?)
• Auditor credentials (BPI or RESNET certified costs more)
• Region

Many utility companies offer free or discounted audits as part of efficiency programs. Check with your utility before paying out of pocket.

What You’ll Typically Find

Common audit findings across U.S. homes:

• Attic insulation: Often well below recommended R-value; see our attic insulation guide
• Air leaks: Around can lights, rim joists, attic hatches, and penetrations
• Duct leakage: Loose connections in unconditioned spaces
• HVAC sizing: Oversized systems short-cycle and waste energy
• Hot water: Uninsulated tanks and pipes
• Windows: Usually lower priority than people assume (upgrading alone rarely pays back)

ROI: Is It Worth It?

Almost always. Most audits identify $500 to $1,500 in annual savings available through modest investments. Even a $400 audit pays back within a year if you act on a few recommendations.

Beyond savings, audits frequently uncover:

• Carbon monoxide risks
• Moisture problems that would have led to mold
• HVAC equipment running inefficiently
• Safety issues with electrical or gas systems

Preparing for Your Audit

• Gather 12 months of utility bills
• Make a list of comfort complaints (this room is always cold, etc.)
• Note any renovation work and when HVAC was last serviced (see our HVAC service prep guide)
• Clear access to the attic, basement, and mechanical rooms
• Plan to be home during the audit — the interview is important

After the Audit

Start with the highest-ROI items: air sealing, insulation, and HVAC tune-ups typically pay back fastest. Window replacements and whole-system HVAC upgrades have longer returns and should come later.

Check for rebates and tax credits before you start. Federal energy credits, state programs, and utility incentives often cover 20 to 50% of qualifying upgrades.

Ready for Help?

A quality energy audit is the smartest $400 most homeowners will ever spend. Trusted home service professionals can conduct a thorough audit and connect you with the right specialists for each recommended improvement.

Get a free quote to start saving.