Home Energy Assessments in the DMV: What a Blower Door Test Tells You

By Max Fisher · Published 2026-10-15 · Updated 2026-10-18

Short answer. Before anyone quotes a heat pump, have the house measured. A certified energy assessor uses a blower door and an infrared camera to find where air and heat escape, checks how the house is ventilated, and gives you a list of fixes in priority order. In Maryland, BGE and Pepco customers can book one through their utility for $100.

This is step 1 of four in the Law of Sequence: measure, seal, insulate, then size and install. Each step changes what the next one needs, which is why the order matters.

Why measuring comes first

You cannot fix leaks you cannot find, and you cannot size a heat pump for a house nobody has measured. The Department of Energy’s consumer guide to air sealing puts the assessment first: a certified assessor finds the air leaks, decides how best to seal them, and then the upgrade work follows. The same guide notes that do-it-yourself checks catch the obvious leaks around door frames and pipes, but there are often many smaller, harder to find leaks elsewhere in the house.

Measuring also protects the rest of the project. If the assessment shows the attic is the biggest problem, sealing and insulating it may shrink the heat pump you need. If it shows the ducts leak, that changes what the installer should quote. Every later step depends on this one.

What happens during an assessment

A walk-through and energy history. The assessor looks at how the house uses energy, the age and type of the heating and cooling equipment, and the condition of the attic, basement and ducts.
A blower door test. A powerful fan mounted in an outside doorway lowers the air pressure inside, so outside air is pulled in through every gap. That gives a measured leakage number and makes the leaks easy to find.
Infrared imaging. A thermal camera shows where insulation is missing and where air is moving through walls, ceilings and around fixtures. DOE lists blower door testing and thermal camera imaging as the techniques certified assessors use to locate leaks.
A ventilation and safety check. DOE notes that assessors can determine how well a house is ventilated to avoid a buildup of moisture or harmful gases. This matters because, as ENERGY STAR warns, sealing a house or its ductwork can cause combustion appliances such as water heaters to backdraft, and those problems should be corrected before any sealing starts.
A written list of fixes. At the end you should receive a report listing the most cost-effective measures for your house. Keep it. It is the document you hand to the insulation contractor and, later, to the heat pump installer.

Who should do it

DOE names two nationally recognized certifications for home energy assessors and contractors: the Building Performance Institute (BPI) Building Analyst certification and the Residential Energy Services Network (RESNET) Home Energy Rating System (HERS) Rater certification. Ask which one your assessor holds, and ask to see it.

The assessor does not have to be your heating contractor. Some HVAC companies have certified staff and run their own blower door tests; others partner with a home performance company. What matters is that the measurement happens before anyone recommends a system size, and that you get the results in writing.

How to book an assessment in the DMV

Maryland

Maryland’s EmPOWER programs run through the electric utility, and BGE and Pepco both run Home Performance with ENERGY STAR programs that start with an in-home assessment. BGE lists the audit at $100, which it calls a $400 value, and says customers who go on to complete upgrades may qualify for rebates averaging $3,000. Pepco lists its assessment at $100 for homes up to 3,000 square feet, with a no-cost option through its moderate income offering. Delmarva Power, Potomac Edison and SMECO customers should check their own utility’s program pages, and income-qualified households should ask about free assessments.

Northern Virginia

Dominion Energy customers can start with Dominion’s energy saving programs, which list a home energy audit through participating contractors, a virtual audit, and an income- and age-qualifying program with no-cost assessments.

Washington, DC

DC residents should check the DC Sustainable Energy Utility for current home energy programs. Program details change, so confirm current terms on the official page before you book.

Local companies that offer assessments

Several companies in this directory say on their own websites that they do energy audits, blower door testing or air sealing. A few examples: Elysian Energy and Efficient Home in the Laurel area, EDGE Energy in Beltsville and Reston, Home Energy Medics in Arlington, EcoPower Solutions in Baltimore, and Advanced Green Home Solutions in Annapolis. The full list is on the energy audits and air sealing page.

What to ask before you book

Is the assessor BPI or RESNET certified?
Will you run a blower door test and use an infrared camera?
Will you check how the house is ventilated, and test gas or oil appliances for safe venting?
Will I get a written report with the fixes in priority order?
Do you also do the sealing and insulation, and am I free to hire someone else for that work?

What to do with the report

Read the report with the assessor before they leave and ask which fixes matter most for comfort and which matter most for the heat pump. Keep a copy for each contractor you talk to next. When you collect heat pump quotes, give every installer the same report, so each one sizes from the same measured house and the quotes can be compared fairly.

Questions homeowners ask

What is a blower door test?

A blower door is a powerful fan mounted in an outside doorway. It lowers the air pressure inside the house so outside air is pulled in through every gap. The assessor measures how leaky the house is and uses tools such as an infrared camera to find where the leaks are.

Should the HVAC contractor do the assessment?

Either can work. What matters is that the measurement happens before anyone recommends a system size, that the person doing it is certified, and that you get the written results to share with whoever does the next steps.

Is an assessment worth it if I only want a new heat pump?

Yes. The assessment tells you whether the house needs sealing or insulation first, and those changes can lower the heating load enough to change the size of heat pump you should buy. In Maryland it is also the entry point to the utility rebate programs.

What comes next

With the report in hand, the next step is to fix what it found, starting with the air leaks. Continue to step 2: air sealing.