When it comes to designing your own home, there are hundreds of decisions to make. Among the most important is what type of roof to install. Not only does your roof play an important structural role, it also contributes to your home’s aesthetic. But with so many different roof designs to choose from, it can be hard to know where to start.
In this article, we’re taking a deep dive into skillion roof designs—a versatile option suited to a wide variety of buildings, from sheds to extensions to dream homes. We’ll explore what skillion roofs are, the four main skillion roof designs, the pros and cons of skillion roofing and a variety of other commonly asked questions.
What is a skillion roof?
Image from Design Vision Corp
Also known as a ‘shed-style roof’ in Australia, a skillion roof is a roof with one large flat surface, set at a relatively steep pitch. That is, the roof is angled to have a low side and a high side. This makes it very different from a traditional gabled roof which is made of two sloping sides that meet at a central peak. Similarly, the steep angle of a skillion roof sets it apart from other flat roofs which are perfectly horizontal.
In Australia, skillion roofs are commonly associated with sheds and other outbuildings, where they are often used thanks to their relatively fast and inexpensive construction. They are also commonly found on extensions to older buildings. However, skillion roofs are an increasingly popular option among homeowners looking to create a sleek, mid-century modern aesthetic.
There are four variations on the standard skillion roof design
In addition to the standard single-panel skillion roof, there are four other modern skillion roof designs:
- Butterfly roof
- Oval roof
- Split skillion
- Multiple skillion.
More detail about the key features of each of these is provided below.
Butterfly roof or double skillion roof
A butterfly roof is a type of skillion roof comprised of two panels that slope down to a central low point. This has the effect of making the roof look like a butterfly in flight—or the opposite of a traditional gabled roof.
Just like their flat-roof counterparts, butterfly roofs gained popularity in the mid-twentieth century and are often associated with the mid-century modern architecture of the United States.
In addition to creating a graceful aesthetic, butterfly roofs have a number of advantages that make them a popular modern skillion roof design. Firstly, like the standard skillion roof, their sloped surfaces allow for easy installation of solar panels. Secondly, they allow for highly efficient water drainage, as they collect water in the valley between the two panels. This makes them a particularly good option for homes in drought-prone areas. Finally, being set on an angle at both ends of the building means there is additional space for tall windows.
Oval skillion roof
An oval skillion roof is like a standard skillion roof, however instead of the roof being flat, it utilises a curved roof panel. Due to the complexity of designing and constructing an oval skillion roof, they are more costly than a standard skillion roof. This means oval skillion roofs are typically more common in commercial or industrial buildings than residential settings. However, they have some advantages over a standard skillion roof design. Specifically, the curved shape makes them naturally more wind resistant than a standard skillion roof, while the curved shape lends a more organic aesthetic to the building.
Split skillion roof
A split skillion is comprised of two skillion roof panels, offset from each other such that one is higher than the other. Unlike a butterfly roof where the two panels join in the middle, the two panels of a split skillion are separated by a wall that joins the two sections, usually over the middle of the building. The panels of a split skillion roof usually slope in opposite directions, giving the look of a traditional gabled roof with the benefits of a skillion roof. However, they can slope in the same direction.
Multiple skillion roof
A multiple skillion roof design involves using several sections of skillion roof across the building, usually at various heights and sizes. For example, a smaller section of roof sloping down to the right may be used over the entranceway, to contrast against the main skillion roof which slopes the other way.
The four best uses for skillion roofing
One of the biggest advantages of skillion roofing—and one of the reasons it’s become an increasingly popular choice—is its versatility. From new homes, to extensions, verandas to sheds, skillion roofing is customisable and easy to construct.
Here are some of the most common uses for skillion roofing:
- On a new house to create a minimalist aesthetic. The clean lines of skillion roofs—and the graceful silhouette of a butterfly roof in particular—make them a popular choice among new builders. Skillion roofs pair especially well with modern building materials like glass, steel and polished concrete for an industrial-inspired design.
- On house extensions. Skillion roofs pair well with existing roof designs, and can be easily constructed, minimising the amount of re-work required to the existing roof structure. Their ease of construction also helps to keep extensions within both your financial and time budgets. Furthermore, the skillion roof can be customised to suit how you want the extension to flow with the rest of the house. If you want a more seamless flow, skillion roofs are a great option because the angle of the pitch can be easily adjusted to align with the existing roof. On the other hand, a skillion roof constructed from modern materials and set at a unique pitch, can help to emphasise the contrast between the extension and home.
- For verandas and patios. Skillion roofs are a simple way to maximise the amount of light in your entertaining space, while ensuring proper drainage of water when it rains.
- For sheds and car ports. Skillion roofs are one of the fastest roofs to construct, while being as durable and weather resistant as other roof designs making them ideal for industrial structures.
There are five main advantages of skillion roofing
Low cost, easy to install, elegant, and efficient—these are just a few advantages of skillion roofs that have made them a popular choice among modern homebuilders. Below we provide more detail about the five main advantages of skillion roofs.
1. Skillion roofing is lower cost than other types of roof
Whether you’re building a new house, or renovating an older one, it’s easy for the cost to escalate. Being lower cost, skillion roofing is an excellent option for home owners on a tight budget looking to cut costs. Skillion roofing is lower cost than other types of roofing for two main reasons:
- It doesn’t require specialised materials like other roof designs do. Because the pitch of a skillion roof helps drain water efficiently, skillion roofing doesn’t require a rubber skin or other waterproof membrane like a completely flat roof does. Furthermore, you can choose a construction material that fits within your budget—whether that’s a corrugated roof, or bespoke tiles.
- Skillion roofing is easy (and therefore fast) to construct, helping to reduce the labour costs associated with the build. Skillion roofs are constructed using a standard method over rafters making them fast to set up. Furthermore, they do not need to be set into the existing roof if used for an extension, removing the need—and therefore the cost—to rework the roof.
2. Skillion roofing is easier to install than other types of roof
No fancy materials. Simple construction. What could be better? A skillion roof is constructed using a rafter support system. Rafters are long beams that the flat outer surface material will sit on. Rafters are used to provide support to the roof, and are the element of the roof that will determine the roof’s angle. Rafters are a crucial part of the roof’s construction because they help to transfer the load from the roof to the outside walls. Typically, a simple ‘bird’s mouth cut’ is used to connect the rafters to the supporting wall. Because skillion roofing is constructed over rafters using this basic method to achieve the desired angle, it’s one of the fastest roof designs to install. Skillion roofs can also be constructed by the builder on-site, minimising transport costs.
Skillion roofs are also easy to design. Because the roof is comprised of only a single flat surface, and it can standalone from other sections of the roof, there are fewer angles to think about when designing and installing the roof. Coupled with the simple materials required, this makes skillion roofs an ideal choice for DIY builders.
3. Skillion roofing delivers a classy, modern aesthetic
Arguably, the main reason skillion roofs are so popular among 21st century home owners is the timeless, elegant design aesthetic it can help to create inside and outside your home. While skillion roofs have been around for centuries, the design gained popularity in the post-war years of the 20th century, when mid-century modern design ideas about clean lines, minimalism and simplicity rose to the fore.
Today, skillion roofs can be paired with a variety of other building materials and designs to create a bespoke look for your home’s exterior. Paired with glass and metal, skillion roofs help to create a minimalist industrial look. Alternatively, used alongside conventional suburban building materials they blend in seamlessly with existing design.
Skillion roof designs also affect how the inside of your home looks, and can help to create a distinctive interior. For example, being set on a slope means that your interior design can take advantage of extra-height ceilings in certain parts of the house. Similarly, many homeowners seeking a rustic design opt to leave the skillion roof’s supporting rafters exposed for a unique look. Skillion roofs are also ideally suited for skylights, helping to bring warmth and light into the space.
4. Skillion roofing offers excellent water drainage
One of the biggest advantages of skillion roofs is how efficiently and effectively they shed water. Being set on a slope means that water will naturally collect on the lower side of the roof. This is a distinct advantage of skillion roofs over flat roofs, which are prone to having water pooling in them, and therefore require specific water-proofing treatments to prevent leakage into the ceiling. Their ability to easily dispel water makes skillion roofs a particularly good option if you live in a high rainfall area, or alternatively, an area that is drought prone where you would like to collect more rainfall for home consumption.
Depending on the construction of your skillion roof, the skillion design may mean that you require a larger box gutter, designed specifically for capturing water between two sections of roof. For example, if you installed a butterfly roof, where both roof panels slope down to a central point, causing water to run off into the middle of the room, you may require a box gutter to collect and drain the water.
5. Skillion roofing helps to maximise space for solar panels
With electricity costs continuing to rise, designing homes to be as eco-conscious as possible is becoming increasingly important. Alongside their other benefits, skillion roofs have an eco-friendly advantage of providing ample space for solar panels. Contrary to popular belief, a flat roof isn’t the ideal orientation for solar panels because they work best when on an angle—which is why they’re set in such a specific way in solar farms. A skillion roof is therefore a much better alternative to a flat roof because, like a gabled roof, it places solar panels at an appropriate angle. Just like any other roof, the orientation of the skillion roof will be the most important factor to keep in mind if you are considering installing solar panels: generally, north facing roofs are the best for solar panels.
Disadvantages of skillion roof designs
In addition to the advantages of skillion roof designs listed above, there are a few downsides to skillion roof designs that are important to keep in mind when choosing the right roof for your house or extension. More detail about the two main disadvantages of skillion roof designs is provided below.
1. Skillion roofing does not allow for attic space
The most significant downside of a skillion roof design is that it does not allow for attic space. In a typical gabled roof design, the attic is the space above the ceiling, between the two sloping sides of the roof—i.e. the bit inside the triangle. However, because skillion roofs are comprised of only one flat surface, and they are typically set at a lower angle than gabled roofs, they do not naturally create an attic space. This makes them less well suited to homes requiring additional loft space for storage.
2. Skillion roof designs are more prone to wind damage than gabled roof designs
Designing and building a house or extension is a significant investment. Accordingly, durability is often front of mind for homebuyers and builders alike. In addition to rain, wind is one of the key elements your roof will be exposed to over its lifetime, making it particularly important that you choose the right roof for wind if you live in an area exposed to high winds.
Unfortunately, one of the main drawbacks of a skillion roof is that it’s not the best choice in high wind areas. This is because roofs with multiple slopes do a better job of dispersing high winds. So while skillion roofs are a more durable option than a flat roof, it’s less weather resistant than a traditional gable roof.
Five examples of skillion roofs
Below are five examples of skillion roofs that showcase some of the most common skillion roof designs. For each example, we highlight the unique features of each design and the benefits it brings to the building.
The example above demonstrates how multiple skillion roofs can be used across a building, for simple construction in a modern urban setting. The example shows how each skillion roof section can be set at a slightly different angle. It also showcases one of the biggest advantages of a skillion roof—the roof’s ability to be set against another section of the house. This feature—coupled with the relatively inexpensive building materials used—makes them an ideal choice for quick and inexpensive extensions. Finally, the photo demonstrates how the angle of the skillion roof, coupled with setting the roof at a slight overhang from the building, can be effectively used to provide shade to the building. This is not something that would be easily achieved with a standard flat roof.
Image by StockSnap
In the house pictured above a very steeply pitched modern skillion roof is used to maximise the amount of interior space available. By setting the roof at this pitch, the skillion roof design allows for extra-height ceilings which help to create a spacious feeling in an otherwise modestly sized space. This example also demonstrates how the oversized wall required to attain the high point on the skillion roof can be used to maximum advantage by installing additional windows. Adding grey trim to the roof also helps to emphasise the roof’s sleek lines, and connect it with the window frames used throughout the rest of the building.
Image from Tullipan Homes
In the example above, several skillion roofs are used across multiple sections of the building. This house is a classic example of how skillion roofs can be used to cover separate sections of the same building to create a consistent look. It demonstrates a key feature of skillion roofs which makes them easy to construct, which is that the roofs can be standalone, and easily positioned against the walls of existing features. For instance, you can see that the roof over the entranceway sits flush against the shed and front room walls, without any requirement for complex building alterations.
This example also illustrates how guttering works with skillion roofs. Because the middle two roof sections slope downwards towards the front of the house, the gutter is attached on that edge, and connected to a downpipe to easily move water away from the roof. By comparison, there is no downpipe attached to the high wall of the front right section of the house because the skillion roof sheds water in the opposite direction.
Image from The Design Writer
The skillion roof in the house above is an example of minimalist design at its best. As you can see through the top window, this modern skillion roof has been carefully designed to give the impression of sitting gently on top of the rest of the structure. This example demonstrates how skillion roofs can be paired with industrial building materials—exposed brick and steel—to create a modern design. Again, the skillion roof is set slightly beyond the building to create shade, and the additional wall height has been used to install windows to maximise the amount of natural light in the building. The high point of the skillion roof has also been angled towards a nice aspect of the property to maximise the view.
Image from Design Vision Corp
In the example above, a skillion roof is used for the main section of the building, while a flat roof is used above the garage and the front of the house. In this design, the skillion roof is set at a relatively high angle, to allow for additional height in the entranceway. This extra wall space has been cleverly converted into a window to maximise the amount of natural light in the home. This example demonstrates several key aspects of skillion roof designs. Firstly, it showcases the additional wall height required to fit in a skillion roof set at a steep pitch. Secondly, this example showcases how the skillion roof can be easily customised to fit with other key design elements. In this case, grey trim is used on the roof to pick up the grey of the brickwork. Finally, this example demonstrates the narrow thickness of skillion roofs, which makes them ideal for installing skylights.