From its humble storage shed origins, the skillion roof has risen to popularity as a sophisticated choice for modern homes. It’s versatile enough to suit a range of minimalist architectural styles, and its durability and low cost make it exceptionally practical.
Also known as a shed roof, lean-to roof or mono-pitched roof, a skillion roof consists of a single flat surface with a steep pitch toward one side. It’s essentially a flat roof with one side higher than the other. In addition to the standard one-section style, these roofs come in several other styles.
Split Skillion – This roof is comprised of two separate sections, with one set higher than the other. A vertical wall joins the two sections, typically somewhere over the middle of the house. The sections usually slope in opposite directions, but occasionally slope in the same direction. When they slope in opposite directions, the roof looks similar to a traditional gable roof, but instead of meeting at a peak in the middle, the two halves of the roof are offset.
Multiple Skillion – This design uses several sections of roof, typically three to five, at varying heights and in varying sizes.
Butterfly (Double Skillion) – Named for the shape of a butterfly’s upraised wings, this V-shaped roof is made of two sides that slope steeply downward to form a valley running between the front and back of the house. It’s specifically designed to collect rainwater that’s then directed into a holding tank. It stands up well to high winds, but it’s more expensive and harder to install and maintain than most traditional roofs.
Standing seam metal, asphalt shingles, and roll roofing are popular material choices that contribute to the skillion roof’s modern vibe. For a more traditional look, wood shakes and clay tiles work well.
A Fresh New Look for a Utilitarian Design
The lean-to style roof is centuries old, but it became particularly popular in Victorian England for use on home extensions. From there, it was exported to Australia, where the term “skillion” refers to a lean-to used as an extra room or storage shed. Because these small buildings are built against the wall of another, larger building, a full traditional gable or hipped roof would only waste space. Instead, these buildings need only “half” a gable roof with the peak attached to the main building’s wall.
Although the roof was widely used for home extensions, it wasn’t until the middle of the 20th century that it really caught on for use on free-standing buildings. With its simple profile, the style fit with Mid-Century architecture’s focus on flat planes, but offered several advantages over the standard flat roof that was popular at the time. Today, these roofs are used around the world to lend a contemporary look to homes and businesses in both suburban and rural areas.
Contemporary Appeal with Moderate Maintenance Demands
The main appeal of a skillion roof is its modern aesthetic. It combines a striking form with a restrained sophistication that’s ideal for any architectural style that emphasizes minimalism. The roof’s simplicity complements a variety of landscaping styles, giving you more freedom to experiment and change up your landscaping when the mood strikes.
It allows for a range of slopes from a steep 9/12 to a flatter 3/12 slope, although your choice affects what roofing materials you can use. Standing seam metal and rubber are good for a low-pitched roof, but asphalt shingles and clay tile require a roof pitch of at least 4/12 unless special underlayment is used.
Affordability is another big benefit of the skillion roof. The style requires less material than most traditional roofs and is also easier and quicker to build, all of which brings down the cost.
A skillion roof with a steep slope provides excellent drainage. This reduces the risk of leaks and other water damage. If you love the sleek look of a flat roof, but don’t want to deal with the drainage issues, a skillion roof is an excellent alternative.
The style is easy to customize. The long, flat plane provides plenty of space for skylights, which give you more natural light indoors and reduce your energy costs. It also accommodates solar panels to lower your energy bills even more. The single low edge makes it easy to collect rainwater for your lawn and garden. By orienting your house with the low side of the roof toward the street or your neighbors, you limit the view into your house and give yourself more privacy.
A skillion roof is overall more durable than a flat roof or even a gable roof. While it’s as vulnerable to wind damage as a gable roof, you can reduce the risk by orienting the roof in a way that reduces the effects of the prevailing winds. If your area is prone to storms, consider using a multiple skillion roof for greater wind resistance.
Because drainage is all on one side, these roofs require a little extra attention to maintenance. You’ll need box gutters, which consist of wood framing lined with thin galvanized steel sheet metal. These gutters are wider and stronger than average, so they can handle heavy rain flow, but they also need more frequent cleaning to prevent clogs.
A skillion roof doesn’t allow for a traditional attic because the ceiling of your living space follows the slope of the roof. If you want to maximize your overhead space, a partial loft is still an option.
Its austere appearance doesn’t suit every home, but for Mid-Century, Minimalist, Industrial, and other architectural styles that put simplicity at the fore, the skillion roof is a practical way to get a modern look while keeping costs and maintenance requirements low.