A.Bill Rose, architect and building researcher at the University of Illinois in Urbana-Champaign, responds: Although many building codes require attic ventilation, there are more important factors than ventilation when it comes to designing an attic and roof system that works well. First, be sure the following points have been covered:

And ventilation? For hip-roof homes, I’ve had occasion to recommend soffit plus mushroom vents, soffit only, and no vents at all, depending mostly on the predisposition of the client. Clients concerned about strictness of code enforcement and shingle warranties should have ventilation by the book, and should have simple designs to match the...

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