Brian Butler

Latest Articles by Brian Butler

How To
Tightening Up a Two-Family House
9 MIN READ

$Both the owner’s downstairs apartment and the rental unit upstairs received new high-efficiency windows, dense-pack cellulose in the uninsulated framing cavities, and a thick exterior layer of rigid foam. Airtight drywall and an additional layer of cellulose in the lower unit increased the R-value of the wall system only modestly — but reduced air infiltration to a fraction of that in the unit above.$