Fitting a pair of roof windows is often possible, but the roof has to be able to take it. We explain the points that decide whether it works.
Bungalows and houses with converted lofts are common in Hengrove, and a pair of roof windows can transform a dark space. The roofs here are often hipped, which changes how much clear slope is available. A pair is a bigger job than a single window, so the structure and the flashing need planning together.
What the roof has to carry
Two windows side by side means a wide opening in the roof. Rafters may need trimming and doubling up around it so the load is carried properly. We look at the size, spacing and condition of the existing timbers in the loft before we say whether a pair is sensible, and how it should be arranged.
Hipped roofs and bungalow slopes
On a hipped roof the slopes are shorter and the hips cut across them, so there may be less room for a wide pair than on a plain gable roof. Bungalow slopes are often large and clear, which helps. We measure the slope and the room beneath, then check the windows will sit where they give the best light.
- Clear width on the chosen slope
- Distance from ridge, hip and eaves
- Headroom and view from inside the room
Flashing for a pair
Windows are matched to a flashing kit for the roof covering. For a pair, the kit has to allow for the join between the frames, so water cannot get through the gap. Done properly, it looks like a single neat installation. Done badly, the join between the windows is where the leak begins. The join between the two frames is the part we plan most carefully.
Lining, insulation and vapour control
Inside, the opening needs a proper lining, insulation around the frames and vapour control, so warm damp air does not condense on cold surfaces. This is as important for two windows as for one, and a wider opening has more edge to get right. Decoration and plaster finishing normally follow once the units are weathertight.
Ask what is included and what is left for others to finish, such as plastering and decoration. Knowing the boundary at the start avoids a gap between trades and a half-finished reveal later on. Please ask early. That keeps expectations clear for everyone.
- Insulation packed tight around the frames
- Vapour control sealed at all edges
- Neat lined reveals ready for decoration
What to ask first
Ask for the window sizes, the plan for the rafters, the flashing arrangement and how the roof will be protected while it is open. Fitting roof windows may need planning or Building Regulations checks — we advise before work starts. We will tell you honestly if the roof suits a pair or whether one larger window would work better. If the loft is being converted, tell us the plan for the room as well, so the openings suit the layout.
Frequently Asked Questions
Is one larger window better than two?
Sometimes, because there is less joint to seal and fewer rafters to alter. Two windows give more flexibility in placement. We compare both for your roof and tell you which makes better sense. It depends on the roof.
Will it make the room too bright or cold?
Light levels depend on the size and orientation of the slope. Properly insulated frames and linings keep warmth in. We talk about glazing choices and blinds during the visit. We explain this before work starts.
Can the work be done in one day?
Time depends on the roof and the amount of structural work. We explain the likely stages and what will be left open overnight, if anything, before we start. It depends on the conditions on site.
Talk to our team about VELUX and roof window installation in Hengrove
Every roof is different — the fastest way to get an accurate answer is a quick chat with our team.