I recently purchased a home that is part of a two-unit property. The previous owner finished the attic space, but without insulation. In order to be a usable space, it needs to be insulated. The house is over 100 years old, and there are crawl spaces on either side, open all along the entire length of the roof. There is no separation wall between the units. I'm presuming this space has always served as roof ventilation, as there is no evidence anywhere otherwise. If I build a separation wall and insulate the space, it will compromise the roof ventilation. Obviously I want to avoid this from happening...but, I'd like the usable space!
Can I install a ridge vent in only 'my' portion of the roof, for my unit?
If so, what sort of affect (if any) will it have on the other unit? Which by the way is unoccupied; purchased by a "flipper" who is very slow-going with the remodel! I'm not overly concerned about their opinion, I just don't want to do anything that would come back to haunt me. Thanks for any feedback!