Velux and roof window installation
A roof window is the simplest way to bring daylight into a loft, a landing or a vaulted extension. We cut the opening, trim the rafters, fit the window with its matching flashing kit and make good the slates or tiles around it. We also replace old roof windows and fix leaking ones, which are usually down to a failed flashing rather than the glass.
Fitting a new roof window
We check the rafter positions and pick a window size that works with them, cutting as few rafters as possible. Where a rafter has to be cut, we trim the opening with doubled timbers so the roof stays strong. The window goes in with an insulation collar and a vapour seal, then the flashing kit made for your roof covering, whether slate or a profiled tile, and the slates or tiles are cut and fitted around it.
Most single windows can be fitted from inside the loft and from the roof in a day or two, with internal plastering and decorating done afterwards.
Do roof windows need planning permission?
In England, roof windows on a house usually fall under permitted development if they do not project more than 150 mm from the roof slope, are no higher than the highest part of the roof, and any window in a side roof slope is obscure-glazed and non-opening below 1.7 metres from the floor. Listed buildings, flats and some conservation areas are different. A front-facing window in a conservation area is the one to check first with the council.
In Wales, permitted development rules for roof alterations differ in detail, so check with Wrexham or Flintshire council if you are there.
Leaking roof windows
A roof window that leaks around the frame usually has a flashing problem: the kit was not fitted properly, slates or tiles were cut too short, or debris has built up behind the window and dammed the water. Condensation on the glass, dripping onto the sill, can look like a leak and is a ventilation issue instead. We check which it is before replacing anything.
Velux and roof windows: questions people ask
Can a Velux window be fitted in a slate roof?
Yes. Roof windows have flashing kits made for slate and for profiled tiles. The slates around the window are cut and refitted so they lap correctly over the flashing.
Do I need building regulations for a roof window?
Adding a roof window involves cutting the roof structure, and the window must meet the energy requirements, so it is building work under the Building Regulations. We tell you how it will be signed off as part of the quote.
Can you replace just the glass in a roof window?
On many modern roof windows the glazed sash can be replaced without changing the frame or flashing. Older windows that are no longer made may need the whole unit replaced.
What size roof window should I choose?
As large as the rafter spacing and the room allow, set at a height you can see out of. For a loft conversion, escape windows may be needed for fire safety, which affects the size and position.
Tell us what is happening with your roof
Call, or send a few details and a photo if you have one. We will come back to you, arrange a visit and give you a written quote before any work starts.