Skylight windows are a great addition to any home with an open-plan design or those with an attic conversion. That said, choosing the perfect size skylight can be a challenging task.
The orientation of the room, the skylight’s purpose, and the style are just some factors to weigh in when picking this feature. Here is your comprehensive guide to skylight window sizes and what to consider when installing them in your home. Read on to find out more!
Difference between Skylight Window Sizes
The size of a skylight window directly affects the amount of natural light entering the property. Following this logic, it would be easy to conclude that the larger windows you get, the better. However, this isn’t always the case because there are more differences between the small, medium, and large skylights.
As a general rule of thumb, the size of a skylight window should cover approximately 3-5% of the room’s floor area. For instance, a 130-square-foot space requires a 31-inch by 23-inch skylight, which covers 5 square feet of the room’s surface area. This is a medium-sized skylight, suitable for large spaces with several additional windows, or medium-sized rooms with one or no other windows.
Small windows (covering up to 4.3 square feet with up to the dimension of 19 inches by 31 inches) are great for small rooms, especially south-facing ones.
On the other hand, skylights that cover up to 7 square feet (with dimensions reaching 31 by 31 inches) are suited for medium to large north-facing spaces. This helps maximize sunlight exposure in these areas. For those that aren’t aware, south-facing windows will get a lot more sunlight.
The shape of the skylights also affects the amount of light you can get from them. For example, even a 20 by 20 inches square skylight provides up to 20% more exposure to daylight than a same-sized round skylight.
What Size Skylight Window Is Best for Your Home
The size of the skylight your space needs will depend on several factors.
The first of these to consider is your budget. For a tight budget, a smaller skylight is a more economical solution. That said, for larger spaces, a sizable skylight can be a good investment, as it will save you plenty of money in the long run and add value to your home.
Contemplate how much light you want in the space. Here, the orientation of the room also plays a crucial role. For example, north-facing roofs with possible obstructions in the roof cavity or a neighbor’s property will benefit from larger skylights. Small to medium skylights are recommended for south-facing spaces with no obstacles to avoid overheating.
Lastly, think about the aesthetics of your space and home. For example, smaller windows are more suitable for traditional styles. Whereas modern homes look strikingly good with large frameless skylight windows.
Benefits of Having a Skylight Window in Your Home
There are many reasons for installing skylights. Here are the most common benefits of having a skylight window in your home.
1. Lighting Efficacy
One of the most common reasons owners opt for skylight windows is to improve their room’s lighting efficacy. They’re a particularly good fit for south-facing rooms and areas where there is an abundance of sunlight all year round.
In these conditions, a skylight can reduce your reliance on artificial lighting by up to 60%, reducing your energy bill drastically. The increased amount of sunlight you get from a skylight can also improve your room’s thermal efficiency, another way to save on utility bills.
2. Ventilation
If your property has poor ventilation, installing a properly-sized skylight can help resolve this issue. Skylight windows are much easier to open and close, and some even come with automatic or remote features. This allows for frequent ventilation in any space. In addition, warm air naturally rises towards the window, which you can use to release the stale air and exchange it for fresh air.
3. Health Benefits
Besides letting plenty of fresh air in, skylights also increase exposure to sunlight. This can provide you with a healthy amount of Vitamin D even during the colder months, strengthening your immunity and boosting your metabolism.
Skylights are also farther away from a personal space, allowing you to keep them open even when you’re sleeping during the warmer months. The flow of fresh air during the night is proven to improve sleep and help establish a healthy sleep cycle.
4. Privacy
Privacy is another common reason property owners often opt for skylights. If you live or work in an area where properties are built very close to each other, regular windows won’t allow for much privacy. Since they’re installed on a roof, skylights prevent anyone from being able to look in and cancel noise without having to sacrifice access to natural light.
5. Roof Access
Skylights provide constant access to flat roofs, which can come in handy if you regularly do maintenance of the roof, gutters, or other roof features. It’s also a good option if you have solar panels on the roof, as these also require frequent checks and repairs.
6. Lack of Regulations
The only regulations you’ll need to deal with when installing skylights are building safety rules. You’ll need to check how much glass structure your building is allowed to maintain its structural integrity.
Unlike when installing other windows, you won’t need planning permissions for skylights. The only exception is if the skylight you want to install has specific features that may affect the neighbor’s property.
How Much Does a Skylight Window Cost?
The cost of a skylight depends on its shape, size, and design. You can find smaller off-the-shelf fixed variants for approximately $400, while the larger ones will be at least $600. If you need a custom-made window, you should expect to pay at least $1,200 per meter for a standard variant.
Additional features and professional installation costs can double the price of your skylight. If you have a standard-sized frame, you can opt for a standard window that comes with a detailed installation manual to cut down some of the installation costs.
What Should You Consider Before Purchasing a Skylight Window?
Apart from the sizing, you should also consider a few other factors before purchasing a skylight window.
- Purpose – Think about all the possible purposes for your skylight. Do you need ventilation too, or the increasing light factor is your biggest concern? Do you need constant access to the roof? Or perhaps you wish to improve the appeal of your space, and its market value?
- Placement – Before installing a skylight, you should determine the ideal place for it. Here, you’ll need to take into account the orientation and shape of your space and roof – as well as any possible obstructions for the skylight.
- Compliance – While you won’t need permission to install a skylight, you may need to comply with specific energy ratings and codes provided by the local authorities. For example, in a warm, dry climate, skylights can represent a fire hazard. In this case, you’ll need to ensure that you install windows that adhere to codes meant to prevent fires.
- Overheating – In a moderate to warm climate and south-facing roofs, you should also consider the issue of overheating. To avoid this problem, look for skylights with low U-values. Windows with a U-value lower than 1 are the most efficient in reducing the heat you get from sunlight. Glass with triple glazing is even more effective. These are often recommended for large skylights.
Installing blinds is another popular solution to reduce the heating effects of the daytime sun. Ensuring the skylight windows are easy to open during the warmer months will also help avoid overheating. In warmer climates, building regulations often dictate that the total gazing of the skylights should always be lower than 25% of the floor area to avoid overheating or cooling.
Added Features of Skylight Windows
There are many features that you can incorporate into your skylights:
- Self-cleaning – Recommended for inaccessible windows. The outer pane has a self-cleaning glass that breaks down the debris when it reacts with the sun. The dirt is washed off when it rains.
- Fixed or opening – Fixed skylights are better for security reasons if you don’t require much ventilation. Otherwise, it’s recommended to install a window you can open to allow air to circulate. Manual openings are cheaper, but electric ones are a good solution for inaccessible skylights.
- Blinds – Essential for bedroom skylights or when you need protection from midday sun on south-facing windows. There are motorized or manual blinds that can be incorporated into your skylights.
- Solar glazing – This is an alternative solution for blinds. Solar protection reduces the heat, glare, and fade caused by the sun. It’s particularly recommended for south-facing windows.
- Privacy glass – If you require more privacy, you can opt for skylight glass with an opaque finish. Otherwise, a clear finish works just fine.
- Conservation – Unlike the typical upright solution skylight, conservation skylights sit flush with a pitched roof. These are recommended for conservation areas or old traditional-style properties.
Final Thoughts
Skylights have plenty of benefits, including energy efficiency, privacy, and the lack of planning permission. However, they can also be rather costly, depending on the size and style you need.
The size of the skylight you need depends on several factors. The different sizes have different advantages and disadvantages, it’s a good idea to do a little research and consider all of these before opting for the final product.
