If you own an older Cape Cod home, you have my sympathy. If you’re the type of homeowner who regularly tackles DIY projects, you’ve probably spent weeks chasing air leaks with a foam gun, lying on your back in a cramped attic. And there’s a good chance that, in spite of your efforts, your house still suffers from ice dams.
I’m sorry for your troubles. You deserve better.
If you are thinking of building a new Cape, it’s not too late to get the details right — as long as you’re still at the planning stage.
A Cape is a story-and-a-half design. Most Capes have second-floor bedrooms featuring 4-foot kneewalls and two sections of sloped ceiling. The sloped ceiling sections usually rise to meet a narrow horizontal ceiling in the center of the house. Most Capes have triangular attics behind the second-floor kneewalls and a tiny third-floor attic that is too cramped to stand up in.
Cape-style homes are associated with a famous peninsula in Massachusetts as well as a well-known 17,000-home residential development built in the late 1940s in Levittown, New York. Most of the original Levittown Capes were sold with an unfinished second floor; it was up to the homeowners to figure out how to install insulation up there. You can imagine the results.
What’s wrong with a Cape?
The basic problem with a Cape is that most examples have a poorly defined thermal boundary.
Should the triangular attics behind the kneewalls be considered indoor space or outdoor space? From a building science perspective, the answer is clear — these attics should be inside the home’s thermal boundary. However, most builders don’t have the foggiest idea where the thermal boundary in a Cape belongs. That’s…