Sunsquare: The market leaders in skylight and roof light design and installation


Designing a rooflight might seem like a complicated process, especially if it’s something you’ve not done before. Here, we’re going to cover all of the main rooflight design considerations and hopefully we’ll be able to help you make that initial process a little easier. And remember, you can always give Sunsquare a call if you’d like assistance in picking out the perfect model.


Here, we’re going to take a look at the practicalities of designing a rooflight. What are the main things you need to bear in mind in terms of the rooflight itself?

Rooflight Sizing

Size is one of the major factors involved in rooflight design. Interestingly, many of our customers end up wishing they’d gone slightly bigger than they did, which is something to think on: it’s quite possible you’re underestimating the size of rooflight you’ll need. One of the main concerns (and one of the reasons people often go smaller than they should) is that they’re worried a larger rooflight will increase the temperature of the room. However, there are a number of glazing options - which we’ll cover further down the page - that can prevent any increase, so don’t be afraid to go for a larger model than you originally planned.

The other thing to bear in mind regarding size is not letting the shape of the rooflight impact how big an aperture you select. It’s somewhat of a misconception that by employing a pyramid-style rooflight you can get more natural light from a smaller aperture. Often, the opposite is true! (Of course, if you’re after a pyramid rooflight simply because you love the look there’s nothing wrong with that.)

Rooflight Upstands

These are the frames that the rooflight sits in, and they’re worth examining during the design process. An effective upstand allows the roofing membrane to be properly installed before the light itself, and also allows the rooflight to lean in such a way as to allow water run-off. (It also means that should the light need repairing or replacing at any point in future, the roof won’t get damaged as a result.) Finally, upstands are also a key part of ensuring the light meets the building regulations. When planning your rooflight, ensure you consult your manufacturer about installing an upstand: it’s worth the investment.

Planning permission

Typically, you won’t need planning permission to install a rooflight. (Rooflights usually replace an existing light or form part of an extension that’s already been agreed on.) The Building Regulations do have limits on the amount of glass allowed in a roof design, but rooflights rarely exceed these limits.

If you work with a specialist to design your rooflight, of course, they’ll be able to advise you on what the limits are.

Rooflight Glazing

There are a number of different types of glazing, and they can all make a big difference to a rooflight’s effectiveness. Here are some of the major types.

Triple v double glazing

Another key consideration is whether double or triple glazing will suit your needs best. Both are great options, and offer a number of benefits over a traditional single pane design:

  • The extra glazing makes a huge difference to thermal performance
  • Extra glazing leads to better noise insulation
  • Double and triple glazing can reduce condensation
  • The extra layers help reduce energy consumption
  • Double and triple glazing tend to be more secure, purely because dealing with three panes is tougher than dealing with one

So, assuming you’re going to go with one of the two, you’re probably curious if triple glazing is really worth the upgrade.

This is largely down to a few key factors:

  • How good the double glazing you’re comparing it to. Sunsquare’s thermally broken glazing – which we’ll cover in the next section – is far superior to ‘standard’ double glazing, meaning the increase in performance of triple glazing might not be as substantial.
  • What your return on investment is likely to be. Triple glazing can offer increased performance. Indeed, some manufacturers have noted that the increase in heat loss can be as much as 50 per cent. Will the money you save be more than the cost of the window?
  • Which frame the glazing is matched with. Remember that while glazing makes a big impact on a window’s performance, the frame can also have a big impact. It’s possible to enjoy outstanding performance with double glazing if your rooflight’s frame is high quality.

Remember that if you’re at all unsure about the right glazing, you can always give us a call.

This isn’t to denigrate triple glazing at all. We offer them at Sunsquare for a reason. The right models can make a real different to your bills.

Triple glazing can allow for a high level of solar heat gain, ensuring that whatever time of year it is, you’ll be able to enjoy a nice warm home without having to deal with UV rays.

It’s also a very secure option: it’s a simple fact that if there’s an extra pane in the window, it’s far less likely to shatter in the event of any impact. Triple glazing is simply a more secure option.

Advanced+ Glazing – the furniture-saving, health-conscious glazing option

Many of our customers want an option that’s somewhere between triple and double glazing. If you were thinking the same thing, you should take a look at Advanced+ Glazing. This isn’t available everywhere, but if you work with a specialist – such as Sunsquare – you’ll be able to include it in your rooflight design.

How does Advanced+ Glazing work?

It’s actually quite simple: an extra film is installed in the airspace of a single glass unit. The result is an increase in performance versus triple glazing, but in a window that’s 33 per cent lighter (indeed, Advanced+ Glazing weighs little more than traditional double glazing!)

What are the benefits?

Advanced+ Glazing blocks 99 per cent of all UV rays that hit it.

This capability means that Advanced+ Glazing can:

  • Give you a cooler home in the summer. It’s particularly ideal in any room which gets a lot of sun at that time of the year.
  • Protect your furniture. Over the long-term, sun rays can warp wood, dry out leather and even cause upholstery colours to fade out.

If these are the sorts of benefits you’re interested in, you should definitely consider Advanced+ Glazing as part of your rooflight’s design.

  • Solar control glazing

Another option is classic ‘solar control’ glazing. As you’ve probably gathered from the name, this form of glazing allows sunlight to pass through the rooflight whilst reflecting the heat that the rays result in. This is great for anyone who wants to brighten up a darker room without having to deal with the inevitable increase in temperature!

This is a very popular option for commercial offices looking to maintain a pleasant work environment without having to spend thousands on air conditioning or waste time fiddling with blinds!

  • Low maintenance glass

It’s also worth mentioning low maintenance glass. This is an option that many manufacturers – Sunsquare included – offer as part of their rooflight design.

Rather than being a specific type of glazing, it’s actually a treatment that can be added to your rooflight.

What are the benefits?

Simple: you’ll spend less time cleaning your light! Indeed, low maintenance treatment can cut down your cleaning time by as much as 70 per cent without affecting your solar gain or the transparency of the glass.

What’s more, low maintenance glass is far less likely to suffer from corrosion than traditional glass. If you can afford it, it’s an investment that’s well worth making.

Opening Options

When it comes to opening options, there are three main choices:

  • Classic rooflights. These models don’t open at all, but don’t let that fool you into thinking they don’t provide a pleasant atmosphere. At Sunsquare, all of our rooflights are BSI Kitemarked for air permeability, weather-tightness and wind loading.
  • Vent rooflights. These models are similar to the traditional models, but also offer the ability to be opened, leaving a gap ideal for encouraging much-needed ventilation into interiors below. These models can be purchased with a range of options, such as windows that open and shut automatically and even those that can detect the weather conditions and operate accordingly.
  • Roof access. If you’d like extra access to your space, then a roof access rooflight could well be the best option. The other benefit of roof access rooflights is, of course, that their ability to open far wider means they allow for even more fresh air to move into the room.

The most popular option at Sunsquare is the ‘vent’, simply because of the versatility. Some people prefer a manual rooflight they can push open, while others want a window that’s already open and letting the cold air in when they get home from work!

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Get in touch

If you’re at all unsure about designing your perfect rooflight, then give Sunsquare a call on 01284 723377. We’re specialists in working with our customers to ensure they get nothing less than the best possible results from any flat roof rooflight installations.

Want to find out more?

If you want to know more about this or anything else then get in contact

Call us on +44 (0)1284 723377

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