Can a Manual Rooflight Be Converted to Electric?

To motorise a skylight, a small electric actuator is fitted to drive the sash open and shut, in place of the handle or pole. It needs a power source, which is either a cable from the mains or a solar panel on the roof, and a control, such as a wall switch or remote.

That sounds simple, but the actuator has to suit the frame. It pushes against the hinges every time it moves, so they must be in good order. The sash must close squarely onto the seal, or the motor will strain against it, and the glass must be sound.

Conversion suits a window that is otherwise in good shape. The frame is square, the sash closes cleanly, there is no sign of misting between the panes and the unit comes from a maker that sells a motorisation option for it.

VELUX roof windows are the most familiar example, and VELUX INTEGRA is the maker's electric and solar range. Other leading makers have similar options. Which models can be fitted with it depends on the year and type of window, so we check the label on the frame rather than guess.

• A relatively recent unit in sound condition: conversion may well be worthwhile.
• A window high above a stairwell that nobody can reach: a motor earns its place straight away.
• A roof window with the wrong sash style for the way you want it to open: swap rather than convert.

We start with the label, then the window itself. A short list of checks tells us whether a conversion is realistic or a waste of money.

1. The make and model, read from the label on the frame.
2. Whether the sash sits square and closes without being pushed.
3. The condition of the seals and whether the sealed unit has misted between the panes.
4. The ceiling lining and where a cable could run, or whether the roof faces the sun for a solar panel.
5. Whether the window can be reached for later servicing of the motor.

A window that fails the first or third check is the usual reason we suggest replacement. If the glass has misted, a motor will not help, and the sealed unit may need replacing anyway, so the bigger job can include the motor at little extra cost. The route for a failed seal is set out under misted and failed rooflights.

An old unit that already shows its age is a poor candidate. Hinges stiffen, seals shrink and the glass may have failed. Fitting a motor to it adds cost to something that is nearly at the end of its life, and you would pay twice when the window itself has to go.

Replacing a whole rooflight or roof window, frame and glass, is notifiable building work, and a new unit has to meet the Part L limit for roof windows, 1.4 W/m²K or Window Energy Rating Band B. A rooflight takes 2.2 W/m²K. If the unit is swapped, the Building Control paperwork is ours to file.

The electrical side decides how neat the job looks. A mains motor needs a cable from the nearest suitable supply, and in a finished loft that may mean chasing a plaster wall or running trunking along a rafter. See electric rooflight wiring for the usual routes.

Solar conversion avoids that. A panel mounted on the unit supplies a small battery, so there is nothing to run through the room. It suits rooms that are already decorated, and we explain how it compares in electric vs solar rooflight.

The cost of converting depends on the same factors as a new electric unit, and you can read about them in our electric rooflight cost answer. For the full picture of what we fit, start at the electric opening rooflights hub.

Controls, sensors and what you gain

Once a rooflight is motorised, the control becomes the part you use daily. A wall switch by the stairs is the simplest. A handheld remote helps in a room where the window is over a bed. Some systems link to an app, though a plain switch tends to outlast a phone setting.

A rain sensor is a natural pairing, because it closes the sash when a shower starts. We cover how it works in rooflight rain sensor. Together they make a high window into something you can leave alone.

The gain is mostly convenience and use. A window that is out of reach stays shut for years, while one at the touch of a switch gets opened every morning. Opening a roof window helps air a room, and it can help condensation clear. That, rather than the motor, is the real reason to do it, and the fresh air rooflights guide shows where opening helps most.