If your house isn’t a full two-stories high, chances are that some of the upstairs rooms are tucked under the slope of the roof. Walking around can lead to a sore head and a crook in the neck, plus there’s the dim light and lack of a view.
If you’ve been thinking about turning an unfinished attic into an office, a mother-in-law apartment, or a couple of bedrooms for your growing family, you’ll be facing the same problems. Roof windows and skylights can help brighten up the space, but you’ll still have to deal with the lack of headroom and view. (It’s hard to look down through a roof window.)
You could raise the entire roof, of course, but that’s a huge project. There’s the cost, the disruption while the entire upper floor is off limits, and the extended period when your house will be exposed to the elements.
The easier solution is to add one or more dormers in the spaces where headroom and light are issues. A dormer is, basically, a projection built onto a roof so the people inside don’t have to bend over in one half of the room. The dormer raises only a portion of the roof. Only the rooms beneath it are involved, and the hole in your roof will be smaller. It also provides a bit of wall for a window or two.
Some of the considerations in adding a dormer are the same as you have for raising the roof: You have to schedule carefully with your contractor so the work will be done at the most convenient time. You have to find room for the people and belongings that normally occupy the space. You have to empty the affected area and seal it off to keep dust out of the rest of the house.
One thing that’s different with dormers is that you have a selection to choose from. Dormers came in three basic types, with variations in each one.
When you look at the end of a house, the triangle beneath the roof (from the eaves, or drip-edge, up to the peak) is called a gable. A gable dormer has the same shape – a triangle that starts at the level of the eaves – but it’s on the side of the roof, and often it’s not as wide as the end gable and doesn’t go all the way up to the peak. Sometimes a gable dormer starts above the eaves, with a short stretch of roof below it, but that’s less common, unless you have . . .
The Doghouse Dormer could be called a subclass of gable dormer, but it has sidewalls, making it look like a doghouse has been stuck through the roof. If the sidewalls are big enough, you might see small windows set into them, but more often they are simply sided with cedar shingles or clapboards to match the style of the house.
Because the roof of a gable dormer follows the roof of the house all the way down to the eaves, it creates another pair of sloping walls to bump your head against. A doghouse dormer will usually avoid this problem. Instead, you’ll have a box-like miniature ell, with full headroom between the two sidewalls.
Another difference between the two is that the gable dormer joins to the roof in two long valleys, one on either side, while the doghouse dormer has short sections of valley, joints where its eaves reach the house roof, and then sections where the house roof runs down along the dormer’s sidewalls. The construction of the gable dormer is a little less complicated, and its long valleys provide fewer corners and seams for leaks.
The third basic dormer type is the Shed Dormer, which looks like a lean-to shed rising from the roof of the house. The shed roof doesn’t have a peak; it runs in the same direction as the house roof, but it has a flatter slope, reaching the eaves at a point that is just about the height of the ceiling inside. The shed roof may start at the peak of the house or a little below it, and it may end at the eave or a little above them; either way it has sidewalls along its full width.
The shed dormer can span the entire width of a house or just cover a single room. Except in special cases, it provides full headroom under its entire reach and lots of wall for windows. It has no valleys to worry about, and only the one expanse of roof, so it is generally easier to construct that either the gable or doghouse dormer.
Give all the features of a shed dormer, you have to ask why it isn’t the only kind we see. The answer is usually one of style. A shed dormer, particularly a small one that covers just one room or a portion of one room, often looks very out of proportion. In other cases, it might not match the period or regional style of the house. Style is also a major reason why one would choose a doghouse dormer over a gable dormer.
There are also technical reasons why one dormer type would be more appropriate than others. Putting up a doghouse dormer that would have only tiny sidewalls would be a lot of extra effort and expense over a gable dormer. Putting up a shed dormer with too flat a roof pitch could create problems with snow or ice buildup.
When you begin to notice all of the dormers there are around us, you realize that these are all relatively small issues compared to the problems that adding a dormer can solve. The extra headroom converts into larger and more comfortable living space. The extra light and a view add to the comfort factor, turning a room that seemed small and dark into a very enjoyable place to spend some time.