Greater Lansing
Blower door test
Two people can argue all day about whether a house is drafty. They cannot argue about the reading — and more to the point, they cannot argue about whether the work you paid for changed it.
What is actually wrong
A blower door is a fan in a frame that seals into an external doorway. It pulls air out of the house until the inside is at a set pressure below the outside, and then measures how hard it has to work to hold it there. A leaky house needs a lot of fan; a tight one needs very little. That is the whole idea.
What it gives you is a number rather than an opinion. Two people can disagree all day about whether a house is drafty. They cannot disagree about the reading, and crucially they cannot disagree about whether a job changed it — which is why the test is run before the work and again afterward.
The test takes an hour and a half to two hours and can be done at any time of year, on any house.
Where this stops
When it is not a handyman job
This is at the top of the page rather than the bottom because getting it wrong costs you a wasted visit. Insured, and no contractor license is claimed or implied — the Michigan residential builder license is not held.
- THIS IS A NEW SERVICE WITH NO JOBS BEHIND IT YET. BPI Building Analyst certification is in progress and is not claimed as held.
- A blower door measures how much, not where. The camera and the walk-through find where. Anybody selling the number alone is selling you half of it.
- It is not a mold test, not a radon test and not an air quality test.
- Combustion appliances have to be checked around this work, and where that testing finds a fault the repair is a licensed trade.
The work itself
What actually gets done
Set up and seal the fan into an external door and bring the house to test pressure.
Measure total leakage and record it in a form that can be compared to the same house later.
Walk the house while it is under pressure, which is when leaks you cannot normally feel become obvious at your hand.
Infrared alongside it, because the fan tells you how much and the camera tells you where.
A re-test after the work, so the money spent has a measured result rather than a feeling.
The documentation where a rebate program requires a tested result.
This work sits inside Air Sealing, which carries the invoiced price bands for the trade with the sample size printed beside every figure.
What it costs
There is no price list for this, and here is what actually decides the number.
The same three words describe a twenty-minute job and a two-day one. Rather than publish a figure that is wrong for one of them, here is what moves it — so you can work out roughly which end of it you are at before anybody comes out.
Whether it is a standalone test or part of a full assessment. A test on its own is much the cheaper of the two.
Whether a re-test afterward is included, which it should be if any air sealing is being done.
The size of the house and how many doors and openings have to be sealed and accounted for.
How to get a real number
Somebody comes out, looks at it properly, and you get a fixed price in writing with the work set out line by line and the exclusions written down as plainly as the inclusions. Coming out to do that is not charged for, and neither is working out what is wrong. If something is found once a wall or a floor is open, it is priced as a written change order and you decide before the work carries on rather than after it is billed. Materials are supplied at cost with the receipt attached, first-time customers get 10% off labor, and labor carries a one-year craftsmanship warranty.
If this is happening right now
What to do in the next five minutes, and what happens when you ring.
Before anybody arrives
- Do not weather strip anything the week before a test. The point is to measure the house as it is.
- Think about whether you want a before-and-after. If any sealing work is planned, a test with no re-test is a number with nothing to compare it to.
- Have the last twelve months of energy bills to hand.
- Expect the house to feel cold while the fan runs. It is pulling outside air through every leak at once, which is exactly the point.
Call the business line
(517) 505-7135Answered Monday to Friday, 08:00 to 18:00. There is no out-of-hours line and this page is not going to invent one — outside those hours, leave a message with the address and what is happening, and it is picked up in the morning.
On the call you get asked what is happening, what else in the building is affected, and whether it is still getting worse. That is how it gets decided whether this is our job at all — and if it is not, you get told that on the phone rather than after somebody has driven out.
- No trip charge
- No call-out fee or minimum
- No diagnostic fee
- No charge for a return visit
True across all 84 written quotes this company has issued. Most contractors in this market charge to turn up.
Or send the detailsWhen the right answer is not this company
- You can smell gas
- Leave the building and call the utility from outside. Not us, and not later.
- Water you cannot stop
- Your main shut-off first, then a licensed plumber. Every minute of this one costs money.
- Sewage backing up, or several fixtures at once
- A licensed plumber with a camera. That is the shared line, not a fixture, and a cable down one sink will not touch it.
- Sparking, scorching or a burning smell at an outlet or a panel
- Breaker off, and a licensed electrician. Electrical work here is repair and like-for-like replacement, and this is neither.
- No heat, or heating and cooling equipment that has failed
- A licensed mechanical contractor. That trade is not offered here at all, and knowing that in one phone call is worth more than a visit.
Questions people actually ask
What is a blower door test?
A calibrated fan is sealed into an external doorway and used to lower the pressure inside the house. How hard the fan has to work to hold that pressure is a direct measure of how much the house leaks. It takes an hour and a half to two hours and can be done in any season.
What does the number mean?
On its own, not much — it means something next to the size of the house, and next to the same house after work. That is why the useful version of this test is run twice. A single reading with no comparison is a fact without a use.
Will it tell me where my drafts are?
Not by itself, and that is the honest limit of it. It tells you how much air is moving in total. Finding where takes walking the house while the fan runs, with infrared, which is when leaks you could never feel on a still day become obvious.
Can it be done in summer?
Yes. The test works in any weather and at any time of year. Infrared imaging alongside it works best when there is a decent temperature difference between inside and out, so a cold morning gives a clearer picture, but the measurement itself does not care.
Book a blower door test
Say roughly how big the house is and whether you want the test on its own or as part of a full assessment. Do not weather strip anything in the week before — the point is to measure the house as it actually is. If any sealing work is going to follow, ask for the re-test at the same time, because a reading with nothing to compare it against proves nothing either way.