With most of the rough mechanical, electrical, and plumbing work (MEP) complete, it was time to test the Grant Residence Passive House for air tightness.
We scored approximately 0.75 air changes per hour (ACH) at 50 pascals (PA) of pressure. Although this is four times tighter than the current energy code requires–it’s not good enough for Passive House, which requires a reading no greater than 0.60 ACH@50PA. So we still have some tightening up to do.
The bad news is that the testing did not reveal any major leaks. That means mitigating that last little bit will be extremely difficult.
On top of that challenge, the items yet to be installed–the drier vent and the fireplace flue–are inherently leaky.