In the northwest corner of Arkansas where I work, most cupolas you see are rotting away on top of dilapidated old hay barns, where the only creatures that seem to enjoy them are the resident cows. So I was a bit surprised when a client approached me about building a cupola on the roof of her home. This cupola would not be functional for ventilating the building below, like those on the barns, although it could have been had I used a different installation strategy. Instead, it would be purely decorative—a way to dress up an otherwise straight and boring roof.

Before I began building the cupola, I did some research to determine a size that would be proportionate to the roof. On the internet, I found a formula that would work well for this project: Each side should be about 1 1/4 inches wide for every linear foot of roof ridge. The ridge measured 29 feet long, so I decided on a cupola that was 36 inches square.

The construction was actually quite simple. I made the cupola in three parts: a base that would saddle over the ridge, a main section with louvered sides, and a hip roof with surfaces that curved up to a point. I used cedar and exterior-grade plywood for all the components and gave the whole cupola three coats of white exterior paint.