Velux & Roof Window Installation in South West London

Where roof windows earn their place

A rooflight over a side return infill is what stops the new kitchen being darker than the one it replaced, because the extension usually sits between two walls with no scope for windows on either side. Overhead glazing is the only daylight available.

In a loft conversion, roof windows on the front elevation are often the only glazing permitted under permitted development, since a dormer forward of the roof plane is not allowed. On a landing or an internal bathroom with no external wall at all, a sun tunnel is frequently the only way to get natural light in.

• Pitched roof windows, centre pivot and top hung
• Flat roof lanterns and pyramid rooflights
• Fixed and opening flat rooflights
• Walk on glass and floor lights
• Sun tunnels and light pipes
• Conservation rooflights for listed and conservation area property

Why fitting matters more than the window

A roof window is a hole cut in the weatherproof layer of your building, on the surface that takes the most water. The unit itself is rarely what fails. What fails is the flashing, the felt dressing beneath it and the rafters that were cut without being trimmed.

Rafters are structural. Cutting one to make an opening without installing trimmers to carry the load onto the neighbouring rafters weakens the roof, and the sag shows up years later. Every opening we form is trimmed properly and, where the span requires it, calculated by our structural engineers.

Flashing and the roof covering

Flashing kits are specific to the covering. A slate roof, a plain tile roof and a profiled concrete tile roof each need a different kit, and using the wrong one leaves a gap that will let water in during driven rain.

The underlying felt or membrane has to be cut and dressed into the opening correctly too, so that any water that does get past the tiles is carried back out over the covering rather than into the insulation. That detail is invisible once the window is in, which is why it is so often skipped.

Conservation areas

In conservation areas, and on listed buildings, standard roof windows that sit proud of the roof plane are frequently refused. Conservation rooflights sit flush with the covering and have a central glazing bar, matching the cast iron originals.

They cost more and they take longer to install because the opening has to be recessed into the roof structure. Where your property requires them we will price them from the outset rather than quoting a standard unit you will not be allowed to fit.