Everything Homeowners Ask About Diagnostic Testing

Pricing depends on home size and which tests are bundled in. A standalone blower door test costs less than a full whole-home diagnostic audit that combines blower door, thermal imaging, and combustion safety testing. Submit a quote request and we'll give you a firm number for your home.

A standalone blower door test is useful if you only need an ACH50 number — for example, to satisfy a rebate program's air-sealing requirement. If you want a prioritized, ROI-ranked list of upgrades, a full audit that pairs the blower door test with thermal imaging gives you a much more complete picture for the same visit.

Thermal imaging is typically an add-on to a blower door test or full audit. It's worth it whenever you need to know exactly where insulation is missing or air is leaking, rather than just how much total leakage your home has — it turns a single ACH50 number into a room-by-room map.

In most cases, yes — the audit fee is small relative to the federal tax credits and utility rebates it unlocks, plus the ongoing energy savings from acting on ROI-ranked recommendations. We rank every recommendation by payback period so you can see exactly which upgrades pay for the audit and which are longer-term investments.

Free utility audits are typically a visual walkthrough with a generic checklist and limited instrumentation. A paid diagnostic audit uses calibrated equipment — blower door, thermal camera, duct blaster — to produce certified numbers that satisfy federal tax credit and rebate documentation requirements, which a free walkthrough usually cannot.

We start with a walkthrough to understand your goals and concerns, then run instrumented tests — blower door depressurization, thermal imaging, combustion safety checks, and duct leakage testing as applicable. We conclude with a summary of what we found before compiling the full written report.

Most whole-home diagnostic audits take two to four hours on site, depending on home size and how many tests are bundled in. Standalone tests like a single blower door test are typically faster.

We recommend an adult be present since a blower door test requires temporarily depressurizing the home and access to every room, including closets and mechanical spaces. Beyond providing access, no special preparation is required — you don't need to clean or empty rooms.

A full diagnostic audit typically covers the attic, basement or crawlspace, mechanical room, and every conditioned room in the home, since the blower door test and thermal camera need whole-house access to produce accurate results.

Core instruments include a calibrated blower door with a digital manometer, an infrared thermal imaging camera, a duct blaster for duct leakage testing, and a combustion safety analyzer for homes with fuel-burning appliances.

No. Diagnostic testing is non-invasive — the blower door temporarily seals in your doorway and thermal imaging is a camera scan. We don't cut into walls or ceilings during the audit itself; any exploratory access needed for a specific diagnosis is discussed with you first.

ACH50 measures how many times the air in your home would be replaced per hour if depressurized to 50 Pascals — lower means tighter. A newer home built to modern code might target under 3.0, while an older home from the 1960s-80s often starts in the 8-15 range before any sealing work. We benchmark your number against homes of a similar construction era.

The HERS Index rates a home's energy efficiency on a scale where 100 represents a standard new home built to current code and 0 represents a net-zero energy home. It's calculated by a RESNET-certified rater using modeled or measured performance data including insulation, air leakage, HVAC efficiency, and window performance.

Thermal images use a color gradient — typically cooler colors (blue/purple) indicating colder surface temperatures and warmer colors (red/yellow) indicating heat loss or air infiltration, depending on season and test direction. Your report includes annotated images pointing to specific problem areas, not just raw thermal photos.

A HERS rating produces one standardized, RESNET-certified score used for resale, appraisal, and new construction verification. A general diagnostic audit is broader — it includes the same instrumented testing but focuses on a prioritized upgrade roadmap and rebate documentation rather than a single certified index number.

Results can be affected by weather conditions during testing, whether interior doors were open or closed, HVAC system status, and any recent changes to the home like new windows or added insulation. We document test conditions in your report so results are reproducible and comparable on re-test.

The Energy Efficient Home Improvement Credit (Section 25C) allows homeowners to claim a percentage of costs for qualifying upgrades — insulation, air sealing, and more — up to annual caps, and in some cases requires a qualifying home energy audit as a prerequisite. Your audit report documents exactly which upgrades qualify.

HOMES (Home Efficiency Rebates) calculates rebate amounts from modeled or measured energy savings, while HEEHRA (High-Efficiency Electric Home Rebate Act) targets income-qualified households for electrification upgrades. Eligibility depends on household income and state program rollout — we can help you understand which tier applies based on your audit results.

Often yes, though specific rules vary by program and utility. Many homeowners layer a local utility rebate on top of the federal 25C credit for the same insulation or air sealing project. We flag stacking opportunities in your report so you don't leave money unclaimed.

Yes — this is one of the main reasons to get a diagnostic-grade audit rather than a free walkthrough. Utilities and the IRS typically require documented before/after test data, which is exactly what a certified diagnostic report provides.

It depends on your specific numbers, but air sealing typically has the fastest payback since it's low-cost relative to the energy savings it produces, followed by attic insulation upgrades. We rank every recommendation in your report by projected payback period, not just by severity.

Savings vary by home, but homeowners who act on a full ROI-ranked recommendation list commonly see meaningful reductions in heating and cooling costs. Because we re-test after retrofit work, we can document your actual before/after savings rather than relying on a projection alone.

Thermal imaging combined with a blower door test is the most reliable way to know for certain — it shows exactly where insulation is missing, compressed, or bypassed by air leaks, rather than just estimating based on visible depth.

Air sealing should generally come before adding insulation. Sealing bypasses first means insulation performs as intended afterward, and it also means your post-work blower door re-test accurately reflects the improvement instead of insulation trapping unsealed leaks.

It can, if done without proper testing — a tightened home can create backdrafting risk for combustion appliances and reduce fresh air exchange. That's exactly why we pair air sealing recommendations with combustion safety testing and ASHRAE 62.2 ventilation calculations.

A full audit is typically a one-time or every-several-years event, but a blower door re-test makes sense any time you complete air sealing or insulation work, to confirm the upgrade worked and to document savings for your records.

Before, if possible — a pre-purchase diagnostic audit gives you real numbers to negotiate with or budget around. If that's not feasible, an audit shortly after closing still gives you a clear, prioritized roadmap for your first year of ownership.

Yes — a post-work blower door test is the only way to confirm the sealing actually reduced air leakage and to generate the before/after documentation many rebate programs require as proof of completed work.

A pre-drywall test happens after the building envelope is sealed but before drywall is installed, making it easy to find and fix leaks. A final test happens once construction is complete and confirms the finished home meets code or program requirements for certification.

A general home inspector evaluates overall home condition and safety systems. A certified energy auditor or RESNET HERS rater uses specialized instrumentation to produce quantified performance data — the two serve different purposes and many homeowners use both, at different points in the buying or ownership process.