Short answer
The time a VELUX takes depends on the job, so we give no figure over the phone. Swapping a window in an opening that already exists asks for less than forming a new opening in the slope, and the roof covering, the pitch and any wiring change the picture again. The free survey looks at each, and the length of the job can be talked through then.
Free survey / fixed written quote / Building Control notification handled / 10-year workmanship guarantee
A swap and a new opening are different jobs
A like-for-like swap starts with a hole that is already framed and flashed. The old unit comes out, a window of the right size goes in, and new flashing is set to the covering around it. The roof structure is left as it is.
A new opening is a bigger task. Welsh Government guidance says making the hole will usually mean some change to the framing, and the roof must also take the unit's load, with reinforcing where it cannot. Rafters are cut, and their loose ends are carried on timbers fixed between the neighbouring ones. Only then can the window and its flashing go in.
| Stage | Swap | New opening |
|---|---|---|
| Opening | already framed | cut and trimmed |
| Roof structure | left as it is | altered, then checked for load |
| Flashing | new kit for the covering | new kit for the covering |
| Approval | building work | generally needed |
The roof covering and the pitch
Slates and concrete tiles are covered differently, and the flashing is chosen for whichever you have. An older or patched roof may ask for extra care at the edges of the opening, and that is something you see on the roof, not from a photograph.
Pitch is the other variable. VELUX's low-pitch roof window is meant for slopes between 10° and 20°, so a shallow roof can point to a different product before any fitting starts, and the product shapes how the work goes. The weather also gets a say, since roof work waits on a dry enough day.
Electric and solar windows add a power question
A manual window needs only a hand to open it. An electric one needs a power supply and a control, so a wall switch or remote has to be placed in the room. VELUX also sells solar-powered versions that run without a mains feed. Whichever you choose, the wiring and the switch position are settled at the survey, because they decide how tidy the finished ceiling looks. The electric rooflight wiring guide shows the options.
The room below the roof
Inside, the window needs a finished surround. The lining, the plaster and the decoration around the opening are part of the picture, particularly in a loft where the reveal is cut into sloping ceilings and the finishing has to follow the angles. How much finishing there is depends on whether the new window matches the old size. Our page on VELUX size codes explains how the type sign on the sash tells you that.
Loft rooms bring fire rules with them
A window going into a loft that is becoming a bedroom can widen the job beyond the window. Where a two-storey house gets a loft conversion, the stairway will normally need fire-resisting doors and partitions down its whole length if it had none. A bedroom window may also have to serve as the way out. An emergency escape window needs an unobstructed opening of at least 0.33 m², at least 450 mm high and 450 mm wide, with the bottom of the opening no more than 1,100 mm above the floor. In a roof window, the bottom of the opening may sit 600 mm above the floor instead of the usual 800 mm guarding height.
Whether a roof window works as an exit depends on how it was sized and placed from the start. Whether yours has to be is something the survey raises early, because it can alter the size of the unit and the amount of work around it.
Paperwork that sits alongside the fitting
Some of the schedule is not ours to set. In Wales, adding a rooflight to a house in a conservation area, a National Park, the Gower AONB or a World Heritage Site is not permitted development, so it needs a planning application, and the decision rests with the planning authority. A listed house needs listed building consent where the work affects its character, applied for through the local planning authority. Our guide to planning for roof windows in Wales sets this out.
Where the work is notifiable, we handle the Building Regulations notification with local authority building control or a registered building control approver. A time that fits your own roof comes from the survey: ring 01792 929062 or send the survey request. The VELUX windows page shows the range.