Air-sealing a brick house
I live in a 4-story, 5,000-square-foot, balloon-framed, brick house built in the 1920s or so.
I recently did a pressurization blower-door test on the house and it only reached 20 Pa or so, but I identified some huge places where air is leaking, including the basement ceiling which is open to the floor cavity and 2 closets on the third floor which connect to the attic/outside somehow.
I was about to seal these places up when someone who has a lot of experience with residential energy efficiency told me that because it’s a brick house and therefore has air-tight walls, it would be more worth my time to explore penetrations through the building envelope from the outside.
Is this true? Is the approach to air-sealing brick houses different from sealing houses with typical siding? I don’t know what kinds of penetrations would be obvious from the outside besides doors and windows. Would it be helpful to run a pressurization blower-door test again and look for leaks from the outside?
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