“The report had the attic hatch on page two, with a photo. I had walked past that hatch for years. The second test, after the work, was the one that made the first one worth the fee.”
Hyun J.Air sealing and attic insulation
Deep energy retrofits · Burlington, Vermont
Test the house first. Then fix what the test found.
Every Tamarack job starts with a blower door test, a fan in your front door that shows where the house leaks. You get the written report, and every fix we propose points back to a line in it.
- A written report, yours to keep
- Tested again when the work is done
The deliverable
Page one of a sample report
Each numbered spot is a line in the report: where the leak is, a photo of it and what it would take to close it. Your house gets its own.
- 1
The attic hatch and the top plates
Warm air rises through the hatch and every wall top under it. It is usually the first line in the report.
- 2
The chimney chase
A gap around the flue lets house air straight into the attic. We photograph it from above.
- 3
Window sash and weight pockets
Old double-hung windows leak around the sash and inside the cavity beside it. The report says repair, weatherstrip or replace.
- 4
Where the porch roof meets the wall
A seam that looks closed from the street can be open behind the trim.
- 5
The front door and its threshold
We measure the leak at the door with the fan running and note what the weatherstripping needs.
- 6
The rim joist, where the wall meets the foundation
A long, hidden seam that the smoke pencil finds from the basement.
A sample page for a house like this one. Yours lists what the test finds in your house.
In this order
Five steps, and the test comes first
- 01Day one
Step 1: The blower door test
We set a fan in an exterior door and pull the house to a steady pressure. The number it reads is how leaky the house is, before anything is touched.
- 02Day one
Step 2: The leak hunt
With the fan running, we walk the house with a smoke pencil and a thermal camera and photograph each leak: hatches, chases, sills, outlets.
- 03A week later
Step 3: The report and the plan
You get the report in writing. We go through it with you, line by line, and rank the fixes in the order they should happen.
- 04Your schedule
Step 4: The work, air sealing first
Seal the leaks, then insulate, then look at the windows and the heating. Each change is tied to a line in the report.
- 05Last day
Step 5: The test again
When the work is done, we run the same test the same way and give you both numbers.
Why we write it down
The report is the product
A blower door test is only as useful as what you can do with it. So the report is written to be read by you, a neighbor or another contractor, and it is yours when we're done. Our estimate is a second document that points back to it.
In the report
The house's leakage number, measured with the fan running
Every leak we found, with a photo and where it is
A combustion safety check on your furnace or boiler and water heater
The fixes, ranked, with what each one does and what it needs
What we would leave alone
The Vermont year
When each part of the work fits
Blower door tests
The fan works in any season. On a cold day the thermal camera also shows where heat is leaving.
Oct to Mar
Attics and sloped ceilings
Easier to reach when it is neither frozen nor stifling.
Apr to Jun, Sep to Nov
Windows and exterior walls
Siding and sheathing need dry days and above-freezing nights.
May to Oct
Basements and crawl spaces
Rim joists and slabs are work for any month, which fills the gaps.
all year
Heat pump and ventilation work
Best after the house is tight, and before the cold sets in.
Aug to Nov
Typical months for northern Vermont. Your test day sets the real schedule.
What we work on
Six kinds of work, in the order a report usually ranks them
Homeowners
After the second test
“Indira ran the fan and walked me around with the smoke pencil. I could see it pull the smoke out of the sill. Nobody had ever shown me that before.”
Suha H.Triple-decker, basement and rim joists
“We asked for new windows. The report ranked them fourth and said why. We did the first three and kept the windows, with repairs.”
Klaus B.Farmhouse, air sealing and window repair
“The report went to our heat pump installer as it was. He sized the system from it and didn't have to guess at the house.”
Ruoxi Z.Cape, ready for a heat pump
Sample reviews.
Where we work
Burlington and the valleys around it
Five counties, within about an hour of the shop.
- Chittenden County: Burlington, Charlotte
- Washington County: Montpelier, Barre, East Montpelier, Middlesex, Duxbury, Waitsfield, Warren
- Lamoille County: Hyde Park, Morrisville
- Franklin County: Swanton, Highgate, Sheldon
- Addison County: Panton, Weybridge, Shoreham, Addison
We stay within about an hour of the shop on Pine Street. We don't take houses in the Northeast Kingdom, Rutland or Bennington counties, or across the lake in New York. If yours is past that line, we'll say so on the phone.
Before you book
Is the blower door test free?
No. It is a paid visit of about a morning, and the fee is written in your booking before we come. If you hire us, it comes off the contract.
Will the test hurt anything?
No. The fan only changes the air pressure in the house, about as much as a strong wind does. We ask you to have pets secured and windows closed.
Do I have to hire you after the report?
No. The report is yours, and you can take it to any contractor. Many of the fixes in it are things a handy owner can do.
Is my house built before 1978?
Paint in older homes can contain lead. EPA's rule covers paid work that disturbs painted surfaces in those homes. Tell us the year when you book; our certificate is on the certificate and insurance page.
Does a tight house need fresh air?
Yes. The report covers ventilation, and combustion appliances are checked before and after any air sealing so they can't pull exhaust back into the house.
Book a test
Tell us about the house
A few details are enough to book. Or text photos of the attic hatch, the basement ceiling and the thermostat to the number below.
Phone(802) 555-0104
Hours
- Monday – FridayToday
- 7:30 a.m. – 4:30 p.m.
- Saturday – SundayToday
- Closed
Test days are Tuesday to Thursday. We call back the same business day.