A bungalow gives the roof window extra work. If the loft has been turned into a bedroom, the window may be needed as the escape route as well as the view, so its size and sill height are measured to suit. A two-storey semi follows other rules: a converted loft there gets a protected stair for escape, and its roof window only brightens and airs the room. Our VELUX window page explains the range we fit, including the sizes that suit smaller rafter gaps.
The sill height of a roof window is worth settling before it goes in. A sash set too low is awkward to walk past, and one set too high cannot be reached from a bed or a desk, so we mark the position on the rafters with you in the room and check it looks right from where you sit.
Loft space in these houses is often generous. Long, shallow slopes mean a loft can be lit by two roof windows set alongside each other, and the second window gives cross-flow: open both on a warm evening and the loft room clears itself in minutes rather than hours, with nobody needing a fan.
The garden extension that overheats
Plenty of family homes on the estates have a flat-roofed rear addition carrying a fixed rooflight, put in for the brightness. By July the room is warm, and opening the garden door lets in flies rather than relief. The remedy is a rooflight that opens. A flat unit that tilts or lifts, set high over the room, gives the warm air a route up and out, and a second vent on the opposite side of the house gives it a path to follow. In a larger room an opening roof lantern covers a wide area and adds height to a low ceiling.
The rooflight sits high, which makes the controls the main decision. A motorised rooflight with a rain sensor closes when it is needed, and a solar version avoids running new cable into a finished ceiling. For a cost-conscious project the manual version with a pole is simpler, and the cost guide explains the differences.
Inner bathrooms and landings with no window at all are the third group. Fit a sun tunnel and a tube runs from a little dome on the ridge side of the roof down to a diffuser in the ceiling below, and some models add a vent kit. It is the neatest way to light a space that cannot take a roof window.
Where a house has been extended more than once, the survey takes in every roof at the same visit, so the units can be matched and the work sequenced for one team. Each evening the opening is closed in against rain, and your floors stay covered.
If your home is nearer Radstock or Paulton, the house types are much the same, and what is said here holds for them too.