Independent, AI-assisted research · Affiliate disclosure
Efficiency.

Estimator

Air Infiltration Cost Estimator

The air leaking out of your house every year has a dollar value. We'll estimate it based on home age, construction type, and your climate zone — then show you what professional air sealing actually fixes.

Tell us about the house

When was it built?

Knob-and-tube era through early code. Major leakage at top plates and rim joists.

Climate zone
Wall construction

What you're losing

Estimated ACH50

8-15

Air changes per hour at 50 Pa

Leakage rate

2267-4250

CFM50 (cubic ft/min @ 50 Pa)

Annual energy waste

$1,587-$2,975

Heating + cooling, this climate

After professional air sealing

A BPI Building Analyst can typically get a home to 3 ACH50 (850 CFM50) using $1,500-$4,500 in materials and labor. That cuts your leakage cost to $595/yr.

Annual savings (midpoint)

$1,686

Payback (midpoint)

1.8 years

That's an excellent return for an air-sealing project. In Zone 5 climates with a 1940 - 1980 home, this is one of the highest-ROI energy improvements available. Book a blower-door-led BPI audit and ask for a sealing scope.
How we calculate this

ACH50 ranges by vintage come from DOE Building America field data. We assume 8.5 ft ceilings to convert to CFM50.

Cost-per-CFM50 figures are from ENERGY STAR Home Performance program 2025 data, adjusted for climate zone HDD/CDD averages from NOAA Climate Normals 2024.

Wall multipliers reflect that masonry walls leak less by area, while log and manufactured homes typically leak more at joints and connections.

Target post-sealing ACH50 of 3 is the typical achievable result from a one-day BPI air-sealing job. Going below 2.0 ACH50 usually requires invasive work (drywall removal, spray foam) and costs much more.

Last updated: April 2026. Estimator is for planning purposes only. Actual leakage can only be measured with a blower door test. Climate, occupancy, and HVAC configuration affect real-world costs by 30-50%. Consult a BPI- or RESNET-certified auditor before signing a contract.

More on home performance

Real audit walkthroughs, blower door numbers from real homes, and what to do with them.