How To Design Roof Lines

The modern shed roof.

How to design roof lines.

The internal roof lines are called valleys and the external roof lines are the hips as shown. Rather than a single slope a gable roof consists of two slopes that meet at a peak running down the middle of the roof. A cross gable roof is a design that consists of two or more gable roof ridges that intersect at an angle most commonly perpendicular to one another. When matched to the angle and proportions of other rooflines on the house your gable roof will add visual interest and character to the home making the addition look like an asset that belongs with the house.

All you really need to know to get started in thinking about adding a roof line is that it holds up gutters covers rafters keeps animals and the elements from getting into your roof while allowing for ventilation and acts as a finish between roof tiles or shingles and the edge of the eaves. As you can see the 2 lines to the top left of the image are just drawn in approximately. One way to double check that the roof slopes match is to make sure all of the valleys run at 45 to the eave and ridge. We will determine there length in the next.

Shed roofs are another example of clean simple and functional roof structures the simple roof line can lend itself to modernist design quite nicely. It s tempting to cheat the slopes to make the design work in elevation on paper but the built result will fall flat. To start drawing in the hipped roof draw lines at 45 degree angles from all the points on the roof as shown in blue. Shed roofs are best for when you want to let an abundance of light and replace the sometimes impractical attic space with more interior volume.