Why You Should Consider Skylights or Roof Windows

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Some homeowners regard glass windows set into the roofline as a luxury—the construction equivalent of a whirlpool hot tub in a bathroom or an outdoor kitchen on the patio. But skylights or roof windows are much more than a luxury, especially in regions that receive limited natural light, or with house construction where there is a limitation in wall area available for windows.

• In a second-story living space tucked beneath sloped rooflines, the presence of skylights may spell the difference between a bright, friendly space and a murky cave.
• In a home built between closely adjoining neighboring houses, skylights may be the best solution for introducing good natural light into rooms.
• In a one-story house build built with an open-concept floor plan, skylight shafts can bring much needed natural light into the center of large spaces.

Terminology

Homeowners considering some form of glass set into the roofline can sometimes be confused by the various terms they encounter. It doesn’t help when window manufacturers do not use the terms with any kind of consistency. For some, the terms skylight and roof window are entirely synonymous, while for other manufacturers, the differences are notable and important.

While there are precise structure definitions that distinguish skylights from roof windows, in the modern building trades, there are fairly common distinctions made:

• Skylight: A skylight is a fixed window set into the roofline. It may incorporate venting options, but the window itself does not open. In Europe, this type of window may be called a rooflite.
• Roof window: A roof window actually opens usually with a pivoting awning-style mechanism. It may even incorporate window screening, in much the same way as an awning-style window set into side walls. Some manufacturers, however, call this type of window a venting skylight.
• Light shaft: This term refers to a structural adaptation in which a walled shaft passes through between roof trusses or joists to link a room ceiling to a skylight or roof window. This shaft is sometimes called a chase. This is often the construction used in one-story homes, where a horizontal opening in the ceiling is connected to the roof-mounted window by a framed and finished shaft. The framing required by a shaft can add considerably to the cost of a skylight.
• Tube window: This is a simplified and inexpensive form of a light shaft, in which a small bubble dome window set into the roofline is linked to a lower ceiling by means of a flexible reflective tube. A tube skylight is normally used for small spaces to provide outdoor light to a small bathroom, closet, or laundry room. This is a very inexpensive option.

Skylight/Roof Window Options

There are nearly as many options for windows set into the roofline as there are for windows in walls. While operating mechanisms are somewhat more limited (you rarely find sliding windows or double-hung style used in roofs, for example), you have the same options for glazing and glass. Some types of roof windows are operated by remote control motors—which is essential if you want a vented window set high above in a light shaft.

Glass for roof windows and skylights is typically made from highly shatter-resistant glass, since these windows may be subject to impact from hail or falling tree branches. Beyond this, you’ll have options for single, double-, or triple-pane glass, reflective coatings, gas-filled chambers between glass panels, and all the other options common with traditional wall windows.

Installation Options

Just as with traditional windows for walls, you have options for how to install roof windows or skylights. They can be installed yourself, by the window company, or by a traditional carpenter or general contractor.

• Homeowner Installation: If your skylight is small enough to fit between two trusses or rafters, your installation job will be vastly easier than if you need to cut away trusses or rafters. Many roof manufacturers include detailed instructions that make this a job that a skilled DIYer can easily tackle. If you feel comfortable with basic carpentry, shingling, basic window installation, drywall work, and painting—the same skills that go into installing a traditional window in a side wall—you can put in your own skylight or roof window. For motor-driven skylights, you’ll need electrical experience, too. DIY skylight installation is not a project that lends itself to impulsiveness. Be sure to consider your strengths and weaknesses before tackling a job that punches a hole in your roofline.
• Window Company: Any search for replacement windows will soon lead you to qualified professionals who can install skylights and roof windows. Pella, Marvin, and Andersen are among the big names in windows who can not only supply you with a skylight but also the qualified professionals to install it. The big downside here is that most window-only companies will do just that: install the window only. They will require a fully framed-out area in advance so that all they need to do is put in the skylight. Everything else—including the skylight shaft, where necessary—is up to you. For this reason, this is an expensive option. But it is also an option that pretty much guarantees a quality, warranty-backed installation.
• Carpenter or Contractor: Any general contractor, general carpenter, and even an experienced handyperson should be able to install your skylight. This option will be vastly cheaper than going with the window contractor. With this option, the contractor wears two hats: framing the area and also installing the skylight itself. A contractor will outsource activities to sub-contractors (notably, drywall work for the shaft). A carpenter/fix-it person, on the other hand, may do everything alone or perhaps a partner. The best advice here is to make sure to work with a contractor or carpenter based on a recommendation from someone who has used that person successfully.

Limitations to Roof Windows and Skylights

Roof windows and skylights offer many advantages, but they aren’t always a replacement for standard windows on side walls. Keep the following in mind:

• Windows are often required by building code because they provide egress (escape) in the event of emergencies. A skylight or roof window cannot always be used as a replacement for windows. Some manufacturers, however, offer roof windows with the spacing required to qualify as egress openings. There will, however, need to be a means for climbing down off the roof in order for the roof windows to meet the legal requirements for an egress window.
• The «solar gain» on a skylight or roof window is notable. This can be an advantage in cold climates, where the winter sun beaming down on the roof window can help heat a space. But it can be a distinct disadvantage in the summer or in warmer climates. Many skylights don’t come with any kind of blind or method for blocking out the sun. This is an option that will usually cost you more.

Prices

Skylights and roof windows themselves are not prohibitively expensive, especially for DIYers who will be doing the work themselves. At one big-box retail center, recent costs for a fairly large roof window:

• Manually venting Velux roof window, 21 inches x 37 3/4 inches: $506
• Fixes Velux skylight, 21 inches x 46 1/2 inches: $399

These prices are not appreciably more than for good-quality wall windows designed for new construction.

The costs of having a carpenter or contractor do the work can add substantially to the price. Here are recent national averages:

• Cutting a hole in the roof and alter the rafter framing usually costs about $200. This cost can be considerably more for very wide windows that require cutting out rafters and reframing that area of the roof. Choosing windows narrow enough to fit between roof rafters or trusses is a good idea that will keep your costs manageable.
• Installing and flashing the window itself will cost $200 to $300 for homes with asphalt shingles, and 20 to 30 percent more for metal or tile roofing.
• Building a chase (shaft) from the skylight to the interior ceiling will cost $1,000 to $1,500.
• Repainting the ceiling beneath the skylight will cost at least $250 if you hire a pro.

Be aware that labor costs can vary considerably from region to region.

The essential guide to glass: roof, windows, ceilings, rooms

Let the light flood in! Bathe your home in natural daylight, brighten dark corners and add extra living space with glass.

Improvements in glass technology and building techniques mean glass extensions, roofing and sun pipes can flood dark areas with light, increasing the feeling of space in your home and giving uninterrupted views of the garden. Natural light is one of the most desirable qualities a home can have, and throughout history architects have experimented with ways to accentuate and make the most of it.

EXTEND YOUR HOME WITH A GLASS ROOF

From the simplest side return to luxury double-storey extensions, using glass as a roof will transform your home like no other material. Advances in glazing technology have produced larger, stronger, more ecofriendly panes so whole sections of ceiling can be replaced with glass.

Modern architects often use sloping glass panels in small single-storey extensions to create a feeling of space. Instead of light fittings and plaster you can gaze up at an ever-changing sky. While it’s more difficult to use, and also costlier compared to more traditional roofing materials, the impact glass will have on your home can be staggering – even a simple glass lean-to extension can dramatically improve the way you use your home.

Building into the side return lets you extend your kitchen, making the most of the area alongside your house, gaining space without losing any garden area. Adding glass roofing and patio doors will help create an open, airy space and may not be as costly as you would think.

Frameless glazing panels can create a striking modern atrium, while luxury sliding roof sections work well in loft conversions.

Glass does have its drawbacks, however. Even toughened glazing isn’t completely safe from tree branches or cricket balls and, just like standard window frames, even if the glass itself stays strong the seals can begin to leak over time.

• Before you buy Speak to an architect who can advise you on energy efficiency and the strict building regulations surrounding glass. Don’t forget to consider reflective glare. Reflections off the glass roof could disturb your neighbours and it could cause planning problems if they complain. Similarly, in some areas, the light pollution caused by your glass roof at night might disturb the neighbours or children asleep upstairs.
• Cost In a typical side return extension, a flat roof with sealed membrane would cost £2500 to £3500, a pitched (lean-to) roof with slates would set you back £3000 to £4000, and a glass roof is more likely to be between £5000 and £6000.
• Good for Opening up small rooms, bringing light to gloomier sections of the house and giving your home a designer look.
• Avoid If you can’t get to the roof for cleaning. Even self- cleaning glass will struggle with wet leaves and bird droppings. Also, south-facing glass roofs can get too hot in direct sunshine, so be sure to budget for blinds.

PIPE IN THE LIGHT WITHOUT WINDOWS

Every home has at least one windowless room or dark corridor that would benefit from natural light. Roof-to-ceiling tubular skylights, known as solar tubes or sun pipes, are the ideal solution. A reflector dome on the roof diverts sunlight down a mirrored tube in the loft to a diffuser fitting in a room below.

One sun pipe on a summer’s day can produce the same light as a 400W bulb, enough for a dark ensuite or corridor. Most models don’t need any power and can be installed by a competent DIY-er, while others can be bought with bulbs built in for when the sun goes down.

From the outside, the only visible sign is a small reflector dome. Although this ca cause issues with planning consent in a conservation area, Monodraught’s Conservation SunPipe has been designed to look like a Victorian cast-iron rooflight and would please most planning officers.

‘Natural light is an essential part of any home,’ explains Chris Taffs, Director of Solatube. ‘These systems get rid of dark and gloomy spaces from virtually any building, brightening your home. As an added bonus, the extra light will also add value to your home.’

• Before you Buy Think about whether you’ll need planning permission. This is important in a conservation area or listed building. Alternative designs are available to blend in with period features. If you want to do it yourself, consider how you’ll get onto a pitched roof and whether you have the tools and experience necessary. If in doubt, call in a builder or ask the supplier to recommend an experienced fitter. You can’t turn off natural daylight, so think carefully before installing a sun pipe in a bedroom. Ask what size tube is suitable for each room. During full sunshine the pipes can produce a powerful light, brighter than a typical bulb, which could be uncomfortable in a small space.
• Cost A single unit suitable for a small bathroom will cost around £250, including all parts and instructions for DIY installation. Professional fitting will cost from £250, depending on roof access and type of tiles.
• Good for Being more eco-friendly. Sun pipes reduce the need for lighting during the day, saving energy.
• Avoid If you need light at the ground floor of a two- storey house. They can usually only be used on top floors or single-storey homes and there’s a maximum tube length of six to nine metres, which could disrupt the positioning of the light if your roof has a very steep pitch. Don’t use in bedrooms unless you want a very early wake-up call.

OPEN UP YOUR CEILING WITH A ROOF LANTERN

Once the ultimate accessory for a Victorian or Georgian townhouse, timber-framed, roof-mounted windows are making a comeback. They’re an affordable and efficient way to fill your home with natural light.

‘Architects are realising that roof lanterns are quicker to install, and pose fewer problems with building regulations and planning applications,’ says Mark Jones, Design Director at Town and Country. ‘They still bring natural light to dark corners or create fabulous pavilion-style extensions at a fraction of the price of using frameless glass.’

Available in a wide range of shapes, including hipped roof designs, domes, pyramids or octagons, a roof lantern will usually improve the look of the outside of your house and come with either PVCu or timber frames and small panes of highly efficient glass.

If you’re extending the kitchen into the garden, large bi-folding patio doors and a flat-roof lantern can bring as much light into the space as a glass-only design. Since the introduction of tighter building regulations, architects are realising roof lanterns can look fantastic and provide plenty of daylight while still being thermally efficient. A roof lantern will cost less, be easier to install and involve fewer planning issues than modern glass-only extensions.

As with any glass structure, shade and ventilation are very important. Lanterns can be supplied with blinds or solar- reflecting glass – though even with blinds it can be difficult to keep the daylight out. You’ll also need to have a ventilator.

• Before you Buy Make sure your home isn’t overlooked by the neighbours. Glass windows in a flat roof could pose a security risk. Make sure the opening panes can be locked and that the glass is reinforced. Check that the work falls within your permitted development rights and adheres to building regulations. If you’re not sure, check on planningportal.gov.uk. Will you need blinds to keep out all light or just to stop glare on bright days? How will you keep the glass clean? Can your window cleaner reach the panes, or would it be better to opt for self-cleaning glass?
• Cost A top-quality timber-framed roof lantern measuring two by five metres costs around £5400 plus VAT fully installed. A smaller PVCu design can be bought for around £1500, excluding installation. Expect to pay £600 plus VAT for a ventilator and up to £4000 for bespoke blinds.
• Good for Adding huge amounts of natural light using traditional construction methods that are in keeping with period design as well as being incredibly ecofriendly.
• Avoid If you have a very modern style of house. Although modern designs are available, the roof lantern won’t have the same wow factor as an ultra- modern frameless extension.

For more info visit Town and Country; Livingdaylight Ltd

ADD ON A GLASS ROOM

Thanks to exciting new building methods and hi-tech materials, the traditional conservatory is having a makeover. As well as PVCu or wood, you can choose from futuristic aluminium-framed sun rooms and gravity-defying frameless glass boxes.

Until recently, huge reinforced panes of glass were only available for commercial projects but they’re now used for residential builds, too. Panes of up to six by three metres can be used as building blocks held together using tough silicon resin to create frameless structures with unbroken views of the garden.

These structures, although modern, work well on period buildings, providing bright, open living areas. As they’re transparent, they don’t block the view of the original building and its features.

Depending on size and specifications, these modern conservatories shouldn’t need planning permission but, as with any extension, you’ll need to keep the building within your permitted development rights. Also bear in mind that there are limits on the amount of glass you can have in your house, so check with your local council’s planning department.

‘The success of your glass extension depends entirely on the glass you use,’ says Vanessa Tarrier from Cantifix Architectural Glass. ‘To create the stunning frameless box designs, you’ll need to invest in the best possible glass with high- performance coatings to help the room stay cool in summer. Scrimp on the quality of the glass and you may end up with nothing more than a conservatory that’s hard to clean and impossible to keep cool.’

Using the best possible glass is essential for both safety and efficiency – reinforced gas-filled double glazing with heat- reflective coatings will make the difference between a baking hot glass box and an enjoyable living space. Most suitable glass is 6-12mm thick and strong enough to stand on.

Building solely with glass is extremely expensive, but you can achieve the all-glazed look for a fraction of the price using smaller panes and ultra-thin, low-profile frames.

Keeping cool can be a problem, especially as blinds often can’t be fitted to a frameless design and you won’t be able to open a window. Plan plenty of ventilation throughout the rest of the house, or invest in air conditioning.