Your Cape Cod House

Home Energy Matters Services Cape Cod HomesYour “Cape” has a heritage dating back to the early New England settlers, who needed a home that could create a warm and welcoming environment, keeping out the extreme cold and heavy snow of New England. They evolved a practical and economical design with a compact floor plan, a second story whose steeply sloping roofline defined the ceiling, and windows that could be closed with shutters against the winter storms.

Today’s capes were largely built between 1920 and about 1960, and often include roof dormers to give more useful space in the second story bedrooms. Of course, generations of homeowners have built additions and renovated both interior and exterior of these homes.

Cape owners often complain about the second floor being colder than the first floor.  They sometimes assume that the furnace isn’t creating enough heat and want to trade up to a larger size furnace.  Most of the time, though, the problem isn’t with the furnace, rather it starts with the structure of the home and can be fixed by reducing drafts and air flow in the hidden parts of the house, and by adding insulation in strategic places.

A defining feature of the Cape Cod house for energy use purposes are the mini-attics, or “knee-wall spaces” formed at the front and back of the house by the sloping roof and the vertical walls of the second floor rooms which often are only 4 or 5 feet high where they meet the roof.  This knee-wall space can be a problem in several ways.

First, since these triangular spaces are unfinished inside, outdoor air circulates through them from the soffits. In the winter, this cold air chills the backs of the short, second story walls, sucking heat from the rooms inside.  Many capes have doors cut in the knee-wall to allow suitcases or boxes of possessions to be stored. Cold air can leak in around the door if it is not sealed or weather-stripped.

The floor of the knee-wall space causes problems in two ways – it is usually over the ceiling of the first floor rooms below, which means that it will pull heat from the living space.  Second, the floor joists which support the upstairs flooring and to which the ceiling below is attached, form an open cavity where cold air can circulate pulling heat from both first and second floor.

So to reduce energy use in a Cape, we block air movement into the second story space and into the floor/ceiling joist cavity by air sealing the walls and floor and weather-stripping the access doors.  We then insulate the backs of the kneewalls, the backs of the access doors and the floor of the space. The ceiling of the second floor, which is usually finished with wallboard, should also be fully stuffed with insulation to prevent heat loss.

Those frugal early New Englanders would approve!