We supply and fit skylight windows in Fortis Green, from roof windows in pitched roofs to flat roof lights and roof lanterns. This page is for homeowners with a dark room, a loft or an extension who want more daylight from above.
You will learn which type of skylight suits your roof, what the rules say, what shapes the cost and how to keep a roof light dry for years. We fit skylights and double glazing across East Finchley, and this page covers what matters most for homes in Fortis Green.
Every job starts with a free roof survey and a written, fixed quote. You can book your survey here.
Skylights in Fortis Green: local notes
- Typical homes: Victorian terraces and villas, with 1930s semis on the Ringwood Estate
- Planning: Part of the area falls within the Fortis Green conservation area, so windows on the front of houses there should match the original style.
Building control for this area is handled by Barnet Council. The shape of the roof and the way we reach it both affect how we plan your fit. See more of our glazing work in Fortis Green.
Which Skylight Suits Your Roof
Start with the roof. Its pitch, its covering and the space below all decide which skylight will work best.
- Pitched tiled or slate roof: a roof window sits in line with the slope. It uses a flashing kit made for your tile or slate profile. This is the most common job in lofts and top floor rooms.
- Flat or low slope roof: a fixed or opening roof light sits on a raised upstand. The upstand lifts the glass above the roof so rain runs off.
- Flat roof extension: a roof lantern adds height and a lot of light. It works well over kitchens and open plan rooms.
- Walk-on roof light: a flush pane strong enough to stand on. Useful on roof terraces and in tight spots.
Think about what the room needs. A bedroom may need an opening window with a blackout blind. A kitchen may need a vent to let out steam. A hallway may just need fixed glass to bring in light.
Skylight Types We Fit
Roof windows
Roof windows are the classic loft skylight. They come in top hung and centre pivot styles. A centre pivot window turns so you can clean the outer pane from inside. A top hung window opens out wide and can work as a fire escape if it is the right size. We fit them in timber, with white paint or a clear lacquer, or in a white polyurethane finish for bathrooms.
Flat roof lights
Flat roof lights have a frame on an upstand and a sealed glass unit on top. The glass has a slight fall so water drains off. They come fixed or opening, and opening ones can have a rain sensor that closes them when it rains.
Roof lanterns
Roof lanterns are pitched glass roofs that sit on a flat roof. They give a sense of height and let light in from all sides. Slim aluminium frames keep the glass area large. They suit kitchen extensions and orangeries.
You can see our full range on the main skylights page.
Glass and Comfort
A skylight lets in far more light than a wall window of the same size. That is a big plus, but it also means the glass spec matters.
- Low U-value glass keeps heat in during winter. Part L asks for a U-value of 2.2 W/m²K or better on a new roof light in an existing home. Most of our units do much better.
- Solar control glass reflects some of the sun's heat. It helps stop rooms getting too hot in summer.
- Laminated inner pane holds together if it breaks, which keeps glass from falling into the room.
- Self-cleaning outer pane uses rain and daylight to break down dirt.
- Blinds and shutters give shade and privacy. Blackout blinds suit bedrooms, and outer awnings stop heat before it reaches the glass.
Planning and Building Regulations
Most roof windows fall under permitted development. You do not need planning permission if the window does not stick out more than 150 mm from the roof slope and is not higher than the ridge. Side-facing windows may need obscure glass and limits on opening.
Rules are tighter for listed homes, conservation areas and roofs that face the street. You may need consent, and a low profile conservation roof window is often the best fit. We check the rules for your address at the survey.
Building Regulations still apply even when planning does not. Cutting a new opening may need new trimmers in the rafters. The new skylight must meet the U-value rules and, in some rooms, fire escape rules. We handle the building control side for you.
How We Fit a Skylight
At the survey we check the roof covering, the rafter layout and the space inside. We look for signs of damp or rot. We also check access, as some jobs need a scaffold or a tower.
On the day, we protect the room below, open the roof and frame the opening. We fit the frame, the flashing and the glass, then seal and test the unit with water. Inside, we line the opening and make good the plaster around it. Most roof windows take one day. Lanterns and larger jobs take longer.
Our full process, from survey to aftercare, is on our how we work page.
What Shapes the Cost
We do not list fixed prices here, as each roof is different. The main things that shape your price are:
- the type and size of skylight
- the roof covering and pitch
- whether rafters need to be cut and trimmed
- access, such as scaffold or a tower
- glass upgrades, blinds and electric opening
- internal lining and plaster work
After your free survey, you get a written, fixed quote. It will not change unless you change the order.
Pairing Skylights with Other Glazing
Skylights often work best as part of a wider plan. A new roof lantern over a kitchen pairs well with French doors or bifolds to the garden. In a period front room, a new bay window can bring light in at eye level while a skylight lifts the rear of the house.
In older homes, many owners choose timber double glazing to keep the look of the house. Timber roof windows match well with these frames. We can quote for all your glazing in one visit.
Keeping Your Skylight Leak-Free
A well fitted skylight needs very little care. A few simple checks will keep it dry:
- Clear leaves and moss from the flashing and the top of the frame each autumn.
- Clean the glass and frame with warm, soapy water twice a year.
- Check the seals for gaps or cracks.
- Look for stains on the ceiling around the opening after heavy rain.
- Keep vents clear so damp air can escape.
If you spot a leak, call us. Our 10-year guarantee covers the units and our fitting work.
Frequently Asked Questions
Can skylights go on a flat garage roof?
Yes, in most cases. We fit a flat roof light on a timber or insulated upstand. First we check that the roof deck is sound and can take the weight. Felt, rubber and fibreglass roofs all work, as long as the covering is in good order. If the roof is near the end of its life, it may be better to recover it at the same time.
Will a skylight affect home insurance?
A properly fitted skylight should not raise your premium. It is still wise to tell your insurer about any change to the roof. Keep the building control certificate and our guarantee papers safe, as your insurer or a buyer may ask for them. Laminated glass and secure locks help if the skylight is easy to reach from outside.
Can a skylight be fitted as a DIY job?
We advise against it. Cutting a roof means working at height and cutting rafters that hold up the roof. A poor flashing is the most common cause of leaks, and damage can stay hidden for months. A trained fitter will trim the opening, fit the flashing kit and test the seal. The work also needs to meet Building Regulations.
Are there energy ratings for skylights?
Yes. Each roof light has a U-value, which shows how much heat passes through. Lower is better. Many also list a g-value, which shows how much of the sun's heat comes in. A low g-value helps stop rooms overheating in summer. We list both figures on your quote so you can compare units fairly.
Do skylights make rooms too hot in summer?
They can, mostly in loft rooms that face south or west. Solar control glass, outer awnings and blinds all help a great deal. An opening skylight also lets hot air escape from the top of the room. We look at which way the roof faces at the survey and suggest the right mix of glass and shade.