Difficulty with Heating Colonial Style Houses

by Erik North on February 22, 2012

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OK, this is it…last house post…for now.

You would think given the simple ‘Monopoly’ house framing of Colonials that they would have relatively few heating and insulation issues. And you’d be largely right if we were talking about a square, unadorned Colonial. But that very simplicity and styles’ attendant popularity invites homeowners and builders to add.

They add dormers, sunrooms, garages, finished rooms over that garage, recessed lights, cathedral ceilings (heaven forbid, recessed lights in the cathedral ceiling). In other words, folks start with a potentially well-insulated and air sealed box then add the sort of architectural details that mess it all up. So let’s get into the difficulties of heating a Colonial house.

What Are Colonials?

A brief re-hash…A symmetrical face typifies the Colonial look. The doorway is centrally located, possibly with ornate detailings. Windows are evenly spaced on either side, usually as side by side pairs. Colonials are usually two though sometimes three stories with flat gable ends and a sharp peaked roof. Top floor windows are often built into shed dormers. Modern additions include accessories like sunrooms, attached garages and finished rooms over the garage.

Difficulty with Heating Colonials

Shed and Raised Dormers – Shed and raised dormers are a lovely addition to most homes and can raise a bland roofline. They’re also installed right in the path of your attic ventilation. I’ve written a few articles on attic venting (here and here). One necessity is an unobstructed path for air flow from the soffits to the ridge vent (or mushroom or gable vent). Installing dormers is one giant obstruction to that air flow.

What happens then? Assuming the soffit is not sealed (and they never are), the air will flow into the house. Rather than up the roof deck and out the vent, the cold outside air will flow into the floor joists (or wherever air pressure takes it). This can be fixed by pulling down the soffits and sealing each eave bay below the dormers with foam blocks and foam sealant.

Attached Garages/Finished Room Over Garage – I’ve written about garages and finished rooms over them a few times. I’ll hit on the major points here. When you tack a garage onto a Colonial (or any house but they’re near universal with Colonials) the attached garage creates three major thermal bypass air leaks and one major insulation headache.

When attached garages with finished rooms are built, the garage’s ceiling joist is anchored on the Colonial’s vertical framing. There is a marriage (joined) wall between the two structures and often eaves with soffit venting on the first floor top plate, allowing cold air into the garage ceiling cavity.

The cherry on top of this awesome efficiency pie is that because the garage is considered unconditioned space (and very hard to make conditioned), that room is facing cold winter air on five sides – the top, the bottom, and three sides.

Sunrooms – Sunrooms make a very pleasant addition to Colonials, adding plenty of natural light to what can be poorly lit interiors. They also create a funny heating imbalance. The sunrooms are almost piped/ducted for heat but with all the natural heat have no need for it. So how often do I encounter heating systems pumping heat into a room that is already 90 degrees F? All. the. time.

Unless the sunroom is on its own zone and programmable thermostat, the heating system will needlessly pump heat into the room.

Recessed Lights – Homebuyers looooove recessed lights and contractors love to install them (if it sells the house faster, why not). I’ve detailed with problems with air sealing recessed lights previously. I’m not going to complain about recessed lights; I will complain about recessed lights in cathedral ceilings.

Infrared of Recessed Lights

Yep...That's why I don't like recessed lights.

Air sealing recessed lights is a pain in the butt. If the cathedral ceiling is scissor trussed, you’ve got a shot. You’ll have access through the attic to the recessed lights. If built with cathedral trusses, you’ve got problems. Unless you’ve got an extraordinarily conscientious builder, the lights aren’t air sealed and there’s no way short of gouging them out of the ceiling of doing so. Hooray.

Colonials are staggeringly popular and they have a basic, Monopoly-style in their basic form. But the difficulties arise when homeowners and builders start lusting after all those enticing complications.

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