Can rooflights be opened electrically?
Yes. Almost every category of glazed unit that goes into a roof is available with a motor in it, and the electric version is a standard catalogue item rather than a special order. Manufactured roof windows from VELUX, Fakro, Keylite and Roto all have electrically operated variants of their normal size range. Made-to-size flat roof rooflights can be ordered as opening units driven by actuators housed in the kerb. Roof lanterns take opening vents. What varies is not whether it can be done but which mechanism suits the unit, where the power comes from, and whether the roof and the room allow the opening angle the product needs. The full technical treatment sits on the electric rooflight installation page, and this is the short answer to the question people ask first.
Yes, and the option runs across every unit type
The word rooflight covers several different products, and each of them has an electrically operated version with its own mechanism. On a pitched roof, an electric roof window looks almost identical to the manual one beside it because the motor is concealed in the depth of the top rail. On a flat roof, an opening rooflight is a slim framed pane hinged at one edge of the kerb and pushed up by threaded actuators sitting inside the upstand. On a lantern, a single glazed panel or a dedicated vent is motorised while the rest of the structure stays fixed.
The one product family where the answer needs a caveat is the conservation rooflight. The slim cast frame that lets it sit almost flush in a thick stone roof has very little depth in the top rail, so the mechanism often ends up as a visible housing on the inboard face instead of being hidden inside the sash. The outside of the roof stays flush, which is what matters to a conservation officer through Painswick or Northleach, but it is worth looking at a photograph of the internal face before the order goes in.
What a motor does that a handle cannot
Opening a window from across the room is the obvious benefit and the least important one. Three things follow from motorising a sash that no amount of reaching achieves.
The unit closes itself when it rains, because a rain sensor on the outside of the sash drives the closing cycle without anybody present. The unit closes properly, because a motorised locking bar drives home after the chain has pulled the sash fully in, compressing the gaskets harder and more consistently than a hand on a bar. And the unit can be put on a schedule or driven by a humidity or carbon dioxide reading, which turns a window into a ventilation device that operates whether or not anyone thinks about it. A manual sash does none of these, however easy it is to reach.
Pitched roof windows, where the mechanism hides in the top rail
On a manufactured roof window the drive is a chain actuator: a small geared motor pushing a rigid link chain out of a shallow housing built into the head of the sash. The chain is stiff along its own axis and flexible across it, so it coils inside a box perhaps 40mm deep and still pushes a heavy glazed sash open against its gaskets.
Both common opening types take one. A centre pivot sash rotates about a horizontal axis roughly halfway up the frame, so part of it swings into the room as the rest swings out. A top hung sash is hinged at the head and lifts from the bottom, so nothing comes inboard. Stroke length is fixed by the model and typically gives an opening angle in the region of 15 to 25 degrees, which is generous for ventilation and modest compared with the 45 degrees a manual escape unit reaches on its stay. Detail on the chain mechanism itself is on the electric rooflight hub.
Kerb mounted flat roof units, and the sash that lifts rather than pivots
A flat roof rooflight opens in a different geometry altogether. The whole glazed pane is hinged along one edge of the kerb and lifted at the leading edge by one or two spindle actuators, which are threaded rods extending out of a tube as a motor turns them. Two are used across wider units so the pane rises evenly instead of racking across its diagonal.
Because the unit sits close to horizontal, a lift of 300 to 400mm at the free edge produces a genuinely large clear opening, considerably more as a share of the frame than a chain actuator manages on a pitched sash. Shorter stroke versions exist as ventilation flaps, lifting perhaps 150 to 200mm, which are quieter and adequate where background air is the point. The kerb has to be built deep enough to house the actuator and the cable has to arrive inside it before the waterproofing goes over the top, which is covered on the flat roof rooflight installation page.
Roof lanterns, where one pane in the structure moves
A lantern is a framed structure of several sloping planes rising to a ridge, and motorising the whole thing is neither possible nor useful. What gets motorised is either one glazed panel in a slope, hinged at its head and pushed out by a spindle actuator concealed in the rafter bar, or a dedicated vent unit built into the ridge.
Position matters more here than on a single sash. A vent at the ridge sits at the highest point of the room, which is exactly where warm air collects, so it is the most effective place to let heat out on a July afternoon in a kitchen under glass. A vent low in a slope moves far less air for the same opening area. On lanterns over kitchen islands in Cheltenham and the vale, the ridge vent is usually the specification that earns its keep. Sizes and pitches sit on the roof lantern installation page.
The situations where the roof says no rather than the product
Nothing about a motor removes the constraints the building imposes, and a few of them stop an opening unit outright.
- A pitch below the manufacturer’s minimum, commonly around 15 degrees for an in-plane roof window. Below that the unit becomes a kerb mounted one on a small upstand, which changes the mechanism and the projection.
- An opening wider than the clear space between two trusses on the estates at Quedgeley, Abbeydale or Bishops Cleeve. The webs stay whole, so a wider unit needs a designed trimmer and a Building Control submission before anything is ordered.
- A permitted development limit of 150mm projection beyond the plane of the roof slope, which a bulky kerb mounted unit on a pitched roof can breach.
- A sash that intrudes into the room at head height above a stairwell, a bed or a landing, which rules out a centre pivot in that position whatever drives it.
Each of those is a statement about the building rather than about the product, and each of them is settled at survey before a size code is written down.
Gloucestershire positions where electric stops being an upgrade
Reach is what decides it. An adult standing on the floor works a handle comfortably while the frame head is up to roughly 2.1 to 2.3 metres above floor level, and a telescopic rod extends that to something like 3.3 metres. Beyond that, a manual unit is a fixed unit in practice.
The county produces those positions constantly. A rooflight over the stairwell of a three or four storey Cheltenham town house is four metres above the treads with no floor underneath to stand on. A Forest of Dean bedroom at Coleford or Mitcheldean sits under a 45 degree slate slope, and a unit set 1.5 metres up from the eaves with a deep reveal at the head puts the handle beyond 2.6 metres. A cottage bedroom on the wolds has a beam across it and nowhere to stand a stepladder. In all three, the sash either has a motor or it never opens.
How the specification is settled before anything is ordered
The survey takes the measurement that answers the question: floor to frame head, vertically, with the pitch recorded off a digital level and the sash length noted, because the handle on a centre pivot sits at the top of the sash and on a top hung unit at the bottom. On a long sash those two positions differ by close to a metre.
Alongside that goes the power question. Whether the room is finished or open at first fix decides whether a mains cable is straightforward or invasive, and where it is invasive a solar unit with its own panel and internal battery does the same job with no cable at all. Then the control positions, the blind if there is one, and whether a rain sensor is wanted are all fixed in writing. Severn Skylights Gloucester fits electrically operated roof windows and made-to-size opening rooflights across the county on both mains and solar, and the workmanship carries a ten-year guarantee written against the perimeter details it controls.
Next on this subject.
- Question How much does an electric rooflight cost? No figure is published on this site for an electrically operated rooflight, and the reason is that the motor is…
- Question Do electric rooflights need an electrician? A mains powered rooflight does. A solar one does not, because nothing in it is connected to the house supply…
- Question Can you convert a manual rooflight to electric? Often yes, and the answer is decided by the model rather than by how much effort anybody is willing to…
- Question What happens to an electric rooflight in a power cut? Nothing moves. The sash stays exactly where the power left it: closed if it was closed, open if it was…