How to Master the Multi-family Blower Door Test

Hello Corbett,
A need to run a Blower Door test at a 3 house complex here in Greece. The houses are in the row, this means that normally I should have three Blower door devices, in order to measure the house in the middle. But I have only one Blower Door!
Additionally, I will need to hand over a written document (report), in order to certify the construction to the Passive House Institute. Do you have any suggestions?
Best and thanks in advance,
Stefanos

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Hey Stefanos-
Great question! You do not, in fact, need multiple blower doors, because you actually want to include the unit-to-unit air leakage.  The measurement of all uncontrolled air leakage to outdoors and to other townhouses is a valuable one, and it should be the goal especially when building to Passive House (or PassivHaus) standards.  Watch this video for a visual explanation:

The Blower Door Bucket

Sounds like a caveman tool, but it's actually the height of technology. I think this might be my favorite futuristic development of the 21st century so far. Take that, Apple!

Basically, when you're testing the air tightness of new construction multifamily buildings, you'll be moving fast and light (ideally), and getting your testing tools very, very dirty. It's a construction site. So why not rig up a toolkit that fits the purpose? Like a bucket, for example?