04/30/2026
This is what can happen when a project changes mid-build.
The original plan here actually made sense:
Defined air barrier
Consistent thermal boundary
Clear system
Then came a change order.
New space. Different use. Different crew.
And nobody zoomed back out to reconnect the system.
So now you’ve got:
• One part of the house following the original air barrier
• Another part doing something completely different
• And air moving between them like it was invited
Blower door on… fog makes it obvious.
Not because the house was built wrong—
…but because the update didn’t carry the system forward.
That’s the takeaway:
Change orders aren’t the problem.
Uncoordinated change orders are.
If the plan changes, the air barrier and thermal boundary have to change with it.
Otherwise you don’t have a system anymore…
you’ve got pieces.
Save this if you’re involved anywhere between design and install.