DIY Home Energy Audit Checklist: Find Where You're Losing Money (2026)

The average American home wastes $400–$800 per year on energy that escapes through air leaks, thin insulation, and inefficient equipment. A home energy audit finds exactly where that money is going.

Professional audits cost $200–$700. This DIY version is free, takes a Saturday, and finds the same issues in 9 out of 10 homes.

What You'll Need

Required:

• Flashlight (bright, handheld)
• Incense sticks or a stick of smoking incense (air leak detection)
• 12 months of utility bills (or pull them from your utility's app)
• This checklist

Recommended:

• Infrared thermometer ($20–$40) — measures surface temps to spot insulation gaps

Optional:

• Plug-in energy monitor (to measure appliance wattage)
• Smartphone thermal camera attachment ($200–$300)

Part 1: Utility Bill Analysis (30 minutes)

Before you touch anything, the numbers tell you where to look.

Step 1: Calculate Your Energy Use Intensity (EUI)

Divide your total annual energy use (kWh + therms converted to kWh equivalent) by your home's square footage.

• Below 10 kWh/sq ft/year — efficient home, diminishing returns on upgrades
• 10–15 kWh/sq ft/year — average; meaningful improvement possible
• Above 15 kWh/sq ft/year — high usage; significant savings available

Step 2: Find Your Peak Months

Which months spike highest?

• Winter spike → heating system and air sealing are your priority
• Summer spike → AC efficiency and attic insulation
• Both spikes equally high → your home has poor thermal envelope overall

Step 3: Compare to Similar Homes

Your utility bill may show a neighborhood comparison. If you're using 20–40% more than similar homes, your envelope (walls, attic, windows) or equipment is the likely culprit.

Part 2: Exterior Inspection (30 minutes)

Walk around the outside of your house.

Step 4: Check Caulking and Sealants

Look at every joint where two different materials meet:

• Where siding meets window frames
• Where brick or siding meets the foundation
• Corners where two walls meet
• Where pipes or wires enter the house

Flag: Any caulk that's cracked, peeling, or missing. These are direct air infiltration paths.

Step 5: Inspect the Roof and Gutters

• Look for missing, curling, or damaged shingles
• Check if gutters drain away from the foundation
• Look for dark staining on the roof (indicates wet insulation or ice dams in winter)

Step 6: Evaluate Windows

Stand back and look at your windows:

• Single-pane glass (no visible seal between panes) = poor insulation
• Fogged or condensation between double-pane glass = failed seal, trapped moisture
• Gaps between frame and siding = air infiltration

Part 3: Attic Inspection (30–45 minutes)

The attic is where most homes lose the most energy. Be careful — wear long sleeves and a dust mask if there's loose insulation.

Step 7: Measure Insulation Depth

Push a ruler into the insulation at multiple spots. Look up your climate zone target:

| Climate Zone | Recommended R-Value | Approx. Depth (blown cellulose) | |-------------|---------------------|--------------------------------| | Zone 1–2 (FL, TX coast) | R-30 to R-49 | 8–13 inches | | Zone 3–4 (mid-Atlantic, Pacific NW) | R-38 to R-60 | 10–16 inches | | Zone 5–6 (Midwest, Northeast) | R-49 to R-60 | 13–16 inches | | Zone 7 (northern border states) | R-49 to R-60 | 13–16 inches |

Flag: If your insulation is less than 10 inches in zone 4 or higher, adding insulation is likely your highest-ROI project.

Step 8: Inspect for Air Bypasses

Before worrying about insulation depth, look for gaps where conditioned air escapes into the attic:

• Top plates (the wood framing at the top of each wall) — often have gaps where they meet the attic floor
• Can lights (recessed lighting) — older non-IC-rated cans are direct holes to the attic
• Attic hatch — often uninsulated and unweatherstripped
• Chimney — should have a collar where it passes through the attic floor

Flag: Any visible gap where you can see daylight or feel air movement. These should be sealed before adding insulation.

Step 9: Check Bathroom Fan Vents

Bathroom exhaust fans often duct into the attic instead of out through the roof. Look for flex duct terminating in the attic — a significant moisture and air infiltration source.

Flag: Any flex duct that doesn't connect to a vent cap going through the roof or soffit.

Part 4: Basement / Crawl Space Inspection (30 minutes)

Step 10: Inspect Band Joists (Rim Joists)

The band joist is the wood framing where the floor structure meets the foundation walls. It's often uninsulated and a major air leakage point in older homes.

Look for:

• Bare wood with no insulation (common in pre-1980 homes)
• Gaps where the sill plate meets the foundation

Fix: Cut rigid foam insulation to fit each bay and glue in place — typically $100–$250 in materials and a Saturday of work.

Step 11: Check Crawl Space Vapor Barrier

If you have a crawl space:

• No vapor barrier on the soil = moisture entering the home, potential mold, wood rot
• Vented vs. conditioned crawl space — vented is standard but conditioned (sealed + insulated) is often better in humid climates

Step 12: Inspect Ductwork

Look at all accessible ductwork:

• Are joints connected (not pulling apart)?
• Is flex duct crimped or kinked?
• Is there any obvious holes or tears?

Flag: Any disconnected duct joint, hole, or uninsulated duct in unconditioned space.

Part 5: Interior Inspection (60–90 minutes)

Step 13: Air Leak Test — The Incense Method

On a cold, windy day, close all windows and doors. Turn on all kitchen and bathroom exhaust fans to depressurize the house slightly.

Hold a lit incense stick near:

• Window and door frames (especially corners)
• Electrical outlets and switch plates on exterior walls
• Fireplace dampers
• Where walls meet the floor
• Around recessed lights

Flag: Anywhere the smoke wavers, blows sideways, or gets sucked in.

Step 14: Check Window Performance

On a cold day, hold your hand 2 inches from each window. Feel for:

• Cold air movement (air infiltration)
• Radiating cold from the glass (poor insulation value)

Use your infrared thermometer: the center of a double-pane window should be within 5°F of room temperature on a cold day. More than 10°F difference = significant heat loss.

Step 15: Test Doors

With each exterior door closed, try to slip a piece of paper under the door sill. If it slides easily, the door sweep needs replacement. Look for light gaps around the frame — use the incense test here too.

Step 16: Inspect Appliances and Lighting

Walk through and note:

• Incandescent bulbs still in use = easy win ($2/bulb LED replacement, 75% energy savings)
• Old refrigerator (15+ years) = often uses 3× as much energy as a modern ENERGY STAR model
• Clothes dryer — check that the vent duct is clean and not kinked (fire hazard + efficiency issue)
• Water heater — check the temperature setting (120°F is optimal; 140°F wastes energy and risks scalding)

Step 17: Check Thermostat Programming

Is your thermostat programmable or smart? An unprogrammed thermostat that holds 72°F 24/7 wastes $150–$300/year compared to a properly programmed setback schedule.

Part 6: HVAC System (30 minutes)

Step 18: Inspect the Filter

Pull the HVAC filter. A clogged filter reduces airflow, forces the system to work harder, and can cause premature failure. If it's grey and solid, replace it now.

Step 19: Check Supply and Return Registers

Walk through the house and:

• Feel each supply register — air should be blowing strongly
• Check that furniture isn't blocking registers
• Look for registers that blow directly onto a thermostat (causes the system to short-cycle)

Step 20: Listen to the System Run

Turn on heating or cooling and listen:

• Banging or rattling = loose panel, failing blower motor
• Whistling = undersized return air or clogged filter
• Short cycles (turns on/off every few minutes) = thermostat placement issue or refrigerant problem

Scoring Your Audit: Where to Start

After completing the checklist, prioritize projects by ROI:

| Issue Found | Typical Fix Cost | Annual Savings | Payback | |-------------|-----------------|----------------|---------| | Air leaks (caulk + weatherstripping) | $50–$200 | $150–$400 | 0.5–1 year | | Attic insulation (if under R-30) | $300–$800 DIY | $150–$350 | 1–3 years | | LED lighting (if still incandescent) | $30–$100 | $50–$150 | 0.5–1 year | | Smart thermostat | $100–$200 | $100–$300 | 0.5–2 years | | Band joist insulation | $150–$400 DIY | $100–$250 | 1–2 years | | Window replacement (single-pane) | $400–$800 per window | $50–$150 per window | 5–15 years |

Start with air sealing — it's the fastest payback and makes every other improvement more effective.

For a professional-level assessment when the DIY audit reveals major issues, read our professional vs. DIY home energy audit comparison to understand when to call in a BPI-certified auditor.