Home Energy Audit: What to Expect and Is It Worth It?

TLDR: A home energy audit costs $200-$500 privately or is often free through utilities. Auditors use blower doors and thermal cameras to find air leaks and insulation gaps. The report prioritizes improvements by ROI. Most homeowners find 20-30% energy savings opportunities.

What an Energy Audit Includes

Blower Door Test

A powerful fan mounts in an exterior door and depressurizes your home. This exaggerates air leaks, making them easy to find. The auditor measures total air leakage in CFM (cubic feet per minute).

Results indicate how "tight" or "leaky" your home is:

• Tight home: Under 0.25 ACH50 (air changes per hour at 50 pascals)
• Average home: 0.25-0.50 ACH50
• Leaky home: Over 0.50 ACH50

Thermal Imaging

Infrared cameras show temperature differences in walls, ceilings, and floors. Cold spots indicate missing insulation or air leaks. Hot spots show heat loss.

Insulation Inspection

The auditor checks attic, wall, and floor insulation levels and condition. They note R-values, gaps, and moisture issues.

HVAC Evaluation

Furnace/AC age, efficiency rating, and condition are assessed. Ductwork is checked for leaks and insulation.

Appliance and Lighting Review

Major energy users are identified: water heater, refrigerator, lighting. Recommendations for upgrades are provided.

What You Get: The Report

A good energy audit report includes:

• Current energy usage analysis
• Specific problems found (with photos)
• Prioritized list of recommended improvements
• Estimated cost and savings for each improvement
• Available rebates and incentives

The best reports show ROI for each recommendation, helping you prioritize spending.

Costs and Sources

Audit Type	Cost	What You Get
Utility-sponsored	Free-$100	Basic assessment, often limited scope
BPI-certified audit	$200-$400	Comprehensive blower door, thermal imaging
RESNET HERS rating	$300-$500	Official HERS score, detailed modeling
DIY assessment	Free	Basic walkthrough, no testing

Check with your utility first. Many offer free or heavily subsidized audits as part of efficiency programs.

Common Findings

Air leaks (found in 90%+ of homes):

• Around windows and doors
• Recessed lights into attic
• Plumbing and wiring penetrations
• Fireplace dampers
• Attic hatches and pull-down stairs

Insulation problems (found in 70%+ of homes):

• Insufficient attic insulation
• Missing wall insulation (in sections)
• Uninsulated floors over garages or crawlspaces

HVAC issues (found in 40%+ of homes):

• Duct leaks (especially in unconditioned spaces)
• Oversized or undersized equipment
• Old, inefficient equipment

Q&A: Energy Audits

Q: Is it worth the cost?

A: Usually yes. A $300 audit that identifies $500/year in savings pays for itself quickly. Many utilities offer free audits, making it a no-brainer.

Q: How long does an audit take?

A: 2-4 hours for a thorough professional audit. The auditor will need access to attic, basement, and all rooms.

Q: Can I do it myself?

A: A basic walkthrough, yes. But you can't replicate blower door tests and thermal imaging without equipment. DIY misses significant issues.

Q: What should I do before the audit?

A: Have 12 months of utility bills available. Clear access to attic, basement, and HVAC equipment. Note any comfort problems (cold rooms, drafts).

The Bottom Line

A professional energy audit costs $200-$500 but often identifies 20-30% energy savings opportunities. Many utilities offer free audits—take advantage of them.

The audit report becomes your roadmap for improvements. Prioritize by ROI: air sealing and insulation usually come first, followed by HVAC upgrades and appliances.

After the Audit: Taking Action

Once you have your audit report, follow these steps:

Prioritize Improvements

Start with the highest-ROI items. Typically this means:

1. Air sealing: Often the cheapest fix with the best return. Seal obvious leaks yourself or hire a professional for comprehensive work.
2. Attic insulation: Adding insulation to recommended R-values is usually cost-effective within 3-5 years.
3. Duct sealing: If ducts run through unconditioned space, sealing them dramatically improves efficiency.
4. HVAC upgrades: Replace old equipment when it fails, or consider heat pumps for larger savings.

Bundling Work

Contractors often offer better pricing for combined projects. If you need air sealing and insulation, doing both together saves compared to separate visits.

Claiming Incentives

Your audit report helps document improvements for tax credits and utility rebates. Keep all receipts and the original audit report for your records.

DIY Energy Assessment

If a professional audit isn't available or affordable, you can do a basic assessment yourself:

• Feel for drafts: On a windy day, hold a candle or incense near windows, doors, and outlets. Flickering indicates air leaks.
• Check insulation: Measure attic insulation depth and calculate approximate R-value.
• Inspect ductwork: Look for visible gaps, disconnected sections, or uninsulated runs.
• Review utility bills: Compare year-over-year usage to spot trends.

DIY assessments miss hidden issues, but they're free and can identify obvious problems worth addressing.

When to Get a Second Opinion

If an audit recommends expensive improvements you're uncertain about, get a second opinion:

• HVAC replacement recommendations over $10,000
• Spray foam insulation recommendations (expensive)
• Major ductwork modifications

A second audit from a different company provides perspective. Recommendations should largely align; significant differences warrant investigation.

Energy audits are the foundation of smart home improvement spending. Whether free through your utility or a few hundred dollars privately, the insights pay for themselves many times over in targeted, effective upgrades.

Connecting Audits to Clean Energy Goals

An energy audit supports broader clean energy objectives:

Before Solar Installation

Reducing your energy consumption before installing solar means you need a smaller (cheaper) system. A home using 1,200 kWh/month might drop to 900 kWh after efficiency improvements—saving $3,000-$5,000 on solar installation while achieving the same bill offset.

Before Heat Pump Installation

Better insulation means smaller heat pump equipment can handle your heating and cooling needs. This saves on equipment cost and improves efficiency. Many HVAC contractors skip load calculations—an audit ensures proper sizing.

Maximizing Incentive Value

Federal tax credits apply to insulation, air sealing, and other improvements identified in audits. The 30% credit on up to $1,200 in insulation costs means the audit pays for itself in tax savings alone.

Finding a Quality Auditor

Not all audits are equal. Look for:

• BPI or RESNET certification: Industry-standard training and testing
• Equipment: Blower door and thermal camera are essential
• Detailed report: Photos, measurements, specific recommendations
• No sales pressure: Independent auditors don't sell installation services

Utility-sponsored audits are often free but may be less thorough than paid independent audits. Consider both options.

What to Expect During the Audit

A thorough energy audit takes 2-4 hours:

1. Interview: Auditor asks about comfort issues, energy bills, goals
2. Exterior inspection: Check insulation access points, window condition
3. Blower door test: 30-45 minutes to measure air leakage
4. Thermal imaging: Walk through home with infrared camera
5. HVAC inspection: Check equipment age, efficiency, duct condition
6. Appliance review: Note major energy users
7. Discussion: Preliminary findings and next steps

The written report typically arrives 1-2 weeks later with detailed findings and prioritized recommendations.

A home energy audit is the single best first step for any homeowner serious about reducing energy costs. The investment of $200-$500 (or free through utilities) returns 10-50x in targeted, effective improvements. Start here, then proceed with confidence to bigger projects like solar, heat pumps, or comprehensive insulation upgrades.

Understanding Your Audit Report

A quality energy audit report includes several key sections. Understanding each helps you make informed decisions:

Current Energy Profile

Shows your current energy consumption patterns—how much you use monthly, seasonal variations, and how you compare to similar homes. This baseline helps measure improvement after upgrades.

Identified Problems

Specific issues found during the audit, documented with photos and measurements. Each problem includes its location, severity, and impact on energy bills. Common findings include air leaks around recessed lights, insufficient attic insulation, and duct leaks in unconditioned spaces.

Recommended Improvements

Prioritized list of suggested upgrades. Each recommendation includes estimated cost, expected annual savings, and simple payback period. Good reports rank improvements by return on investment so you know where to start.

Available Incentives

Federal, state, and utility incentives available for recommended improvements. The auditor should identify which upgrades qualify for tax credits, rebates, or financing programs.

Real-World Audit Examples

What actual audits find and recommend:

1960s Ranch Home:

• Issue: R-11 attic insulation (needs R-49)
• Issue: 0.8 ACH50 air leakage (very leaky)
• Issue: Single-pane windows
• Priority fix: Air sealing ($1,500) saves $400/year
• Second priority: Attic insulation ($3,000) saves $350/year

1990s Two-Story:

• Issue: R-30 attic (adequate but could improve)
• Issue: Duct leaks losing 20% of heated air
• Issue: 15-year-old HVAC at end of life
• Priority fix: Duct sealing ($800) saves $250/year
• Second priority: Plan for HVAC replacement with heat pump

2010s New Construction:

• Issue: Minor air leaks at can lights
• Issue: Builder-grade water heater inefficient
• Finding: Home is relatively efficient already
• Recommendation: Heat pump water heater ($2,000 after credits) saves $250/year

Combining Audits with Clean Energy Projects

Energy audits maximize value from bigger investments:

Before Solar Installation

Reducing energy consumption through efficiency improvements means you need a smaller, cheaper solar system to achieve the same bill offset. A homeowner who cuts consumption by 20% before installing solar saves $3,000-$6,000 on solar while getting the same monthly utility bill.

Before Heat Pump Installation

Tightening your building envelope allows proper heat pump sizing. Many HVAC contractors oversize equipment without load calculations. A well-insulated home might need only a 2-ton heat pump instead of 3-ton—saving $2,000-$4,000 on equipment while running more efficiently.

Questions to Ask Your Auditor

Before booking an audit, ask:

• What certifications do you hold (BPI, RESNET)?
• What equipment do you use (blower door, thermal camera)?
• How detailed is your report?
• Do you sell installation services? (Independent auditors provide unbiased recommendations)
• What's included in the audit fee?

A thorough energy audit is the foundation for smart home energy improvements. Whether free through your utility or a few hundred dollars privately, the insights guide targeted spending that pays back many times over. This single step can save thousands in avoided ineffective upgrades while identifying the improvements that truly matter.