Can an electric rooflight go above a kitchen?

Two problems make a kitchen different from any other room in the house: warm, wet air, and glazing that sits out of reach. An electric rooflight answers both.

Cooking puts a lot of moisture into the air. A hob under a kettle and two pans can lift the humidity of a room fast, and that water has to go somewhere. Warm damp air rises and collects at the ceiling, which is exactly where an opening rooflight sits. Venting from the top of the room pulls the moisture out at its source, well above head height, in a way an extractor fan on the wall or a window at worktop level cannot match. It also lets the built-up heat off a summer afternoon escape upwards rather than sitting in the room.

Then there is the practical matter of reach. Kitchen rooflights are often over an island, a run of units or the hob itself, with no floor beneath them to stand a pole against. A manual winder or a hooked rod is awkward at best and unusable over a worktop. A motor removes the question entirely. You get a wall switch or a handset, and on most systems a rain sensor that shuts the unit if a shower starts while you are out of the room. That last feature matters more in a kitchen than anywhere, because it is the room you walk in and out of all day.

An electric rooflight above a kitchen has to cope with humid air, so specify it for that from the start rather than fitting a standard unit and hoping.

Ask for a chain or spindle motor rated for the moisture load of a kitchen or a bathroom. Most of the mainstream electric roof windows are already built to sit in a wet room, so this is usually a matter of confirming the specification rather than paying more, but confirm it. A humidity sensor is worth adding on top of the rain sensor: it opens the unit a crack automatically when the air gets too wet, then closes it again once the room has cleared, which keeps condensation off the glass and off the reveals around it without you thinking about it.

The wiring is the part people underestimate. A mains-powered rooflight needs a supply run up into the roof to the motor, and that cable is best planned before the ceiling is closed up, not chased in afterwards. Electrical work of this kind falls under Part P of the Building Regulations, so the connection should be made or signed off by a qualified electrician. Solar-powered opening rooflights avoid the cable run altogether, drawing from a small panel and a battery in the frame, which is a sensible route where getting a supply to the roof would mean tearing into a finished ceiling. Both types take the same rain and humidity sensors. We set out how these units differ, and where each earns its place, on our electric skylight installation page.

A kitchen already makes its own heat. Add a rooflight and you can turn the one room that cooks into the one room that overheats, and if that roof faces south you have built a solar collector over the hob.

This is where a Southend kitchen needs more thought than an inland one. The city faces south across the Thames Estuary, and a very large share of the 1930s semis across Westcliff, Thorpe Bay and Hadleigh have their gardens, and their rear extensions, on the south side. Put a flat-roof kitchen extension on the back of one of those houses, glaze it for daylight because the room is deep, and the glass sees sun from mid-morning until the sun swings west, with reflected light off the water adding to the load on a bright day. A flat roof makes it worse again, because horizontal glazing sees the high summer sun almost square on, whichever way the house is turned.

The fix is the glass specification, not the opening. For a south-facing or flat kitchen roof, ask for solar-control glazing with a G-value of around 0.3 or below, rather than the clear double glazing at roughly 0.6 that comes as standard. The G-value is the proportion of the sun’s energy the glass lets through as heat, so 0.3 blocks roughly twice as much as 0.6. An opening rooflight vents the heat the room generates from cooking; the coated glass stops the heat the sun would add through the same hole. You want both. The glare off the water is a separate nuisance that solar-control glass also takes the edge off. Our energy-efficient skylight installation work is built around exactly this problem, and a kitchen is where it bites hardest.

A new or enlarged rooflight is notifiable under the Building Regulations whatever room it goes above, and a kitchen brings in one extra consideration on the glazing.

Part L covers thermal performance and sets a ceiling on the U-value of the unit, which is the winter measure of how fast heat leaks out. Part K covers safety glazing and guarding. Where glazing sits in a position it could be walked into or fallen against, it has to be toughened or laminated, and over a kitchen that is worth flagging early if the design puts the glass anywhere low or reachable. The electrical side, as above, sits under Part P. On the ventilation itself, a rooflight that opens can count towards the purge ventilation a kitchen needs under Part F, though a cooker hood or extractor is still the right tool for grease and the steam directly off the pans.

None of this needs to land on you. On every installation we make the Building Control notification to Southend-on-Sea City Council, or to the relevant local authority, on your behalf. Rooflights are usually permitted development on a house where they project no more than 150mm beyond the roof plane and sit below the ridge, but flats, listed buildings, conservation areas and Article 4 zones are the exceptions, so it is always worth checking your own address with the local authority before you commit.

Start with which way your kitchen roof faces and whether it is flat or pitched, because that decides the glass before it decides the motor. If it faces south or the extension has a flat roof, plan on solar-control glazing and an opening unit together. If you want the cable run kept out of a finished ceiling, ask about a solar-powered motor instead of mains.

Tell us the orientation, the rough opening size and where the hob sits, and we will come back with a unit, a glass specification and a price for the whole thing. Ring 01702 898232 or request a quote, and we will look at the room the light lands in, not just the hole in the roof.