Brighten up your home with a doghouse (dormer, that is)

Question: I use my attic for storage, but it’s dark. I thought about adding a small roof dormer for light and to improve the appearance of my home. How do I design one?

Answer: Adding a dormer to your home can provide natural light in the attic area, and it looks attractive from the street. You mentioned “a” dormer. Even though one will provide adequate lighting, installing two or more looks much better (if, of course, you have the space).

Once you are building one, installing a second or third dormer is not a lot more work.

These types of small dormers are sometimes called “doghouse dormers,” because they are shaped somewhat similar to a doghouse with a gable roof. They have to be built well enough not to leak water, but air leakage is not a major concern. Attics are supposed to have adequate fresh-air ventilation, so a few air leaks will not harm anything.

The first design concern is the size of the dormer. This primarily depends on the vertical height of your roof, from the gutter to its peak. A larger house will have a greater vertical height.

If possible, there should be at least 1 foot of space from the peak of the dormer roof to the house roof and 1 foot from its bottom to the lower edge of the house roof. This simplifies installation and allows adequate room for flashing, in order to prevent water leaks. It also looks much better if there’s some space at the top and bottom.

Another factor to consider is the size of the windows you want to install. In general, for aesthetic reasons, the dormer windows should be smaller than the size of the windows on the floor below them.

Once you have selected your dormer windows, this will determine the height and width of the front face of the dormer. Now you have to determine the pitch of the dormer roof that allows for the 1-foot clearance under the roof peak. If there is adequate clearance, making the dormer roof the same pitch as the house roof looks best.

It is not difficult to build much of a dormer yourself. Most of the work can be done on the ground or inside the attic if there is enough headroom. Unless you are experienced and comfortable working on the top of a roof, have a professional remodeler do the final installation and finish work.

The most critical measurement when building a dormer is the pitch of the house roof. The best method to measure the house roof pitch is from inside the attic. Select a point on the top of a rafter and measure the run (horizontal) distance and the rise (vertical) distance to the peak.

Use this exact pitch when building the sloped sidewall of the dormers. The rest of the construction is similar to building a miniature framed house.

— Creators.com