Are electric rooflights secure when open?

An electric rooflight opens on a chain actuator or a spindle motor fixed inside the frame. When you stop the sash at a given point, the motor holds it there under its own gearing. It does not drift, and it will not lift if someone pushes up on the glass from a ladder, because the drive train has to be turned by the motor to move at all. There is no external lever, no visible catch and nothing to prise, which is a real difference from a hinged roof window with a manual barrel handle.

When the unit is shut, most electric models draw the sash down onto the seal and hold it closed with the same drive. Better units add mechanical locking points around the frame, so the sash is pinned at several places rather than held by the motor alone. Those locking points are what you want to ask about, because they are the part that resists a determined attempt to lever the closed unit, not the motor.

The upshot is that an open electric rooflight is harder to interfere with than an open manual one. What it cannot do is make an accessible roof unreachable, and that is where the actual thinking has to go.

Most electric rooflights are used at a small ventilation opening, not swung wide. A gap of 50 to 150mm at the top of the room lets warm air escape and is far too narrow for a person to pass through. Set at that opening, the unit ventilates all day and presents no usable gap, which is the setting you will leave it on most of the time.

This matters more on a south-facing roof than anywhere else. Southend faces south across the Thames Estuary, and a rear extension or loft on that side collects sun from mid-morning until the sun swings west. An opening rooflight sited at the highest point of the room lets the hottest air out where it collects, which is genuine summer relief. The opening is doing a ventilation job, so it does not need to be wide, and a narrow vent gap is both cooler and more secure than a fully open sash. Pair that opening unit with solar-control glass and you deal with the heat before it arrives and vent what does get through. Our energy-efficient skylight installation work is built around that combination on south-facing rooms.

Full opening is there for clearing steam quickly or for a fire escape route where the rooflight is specified as one, and those are moments you are in the room, not overnight gaps you leave unattended.

The common worry is an open rooflight left open by accident. Electric units answer that with a rain sensor fitted to the frame. The moment it detects moisture the motor drives the sash shut on its own, usually within seconds, and it does the same on many models if power is about to drop. That protects the room from a passing shower, and it also means an open unit does not sit open indefinitely while you are out.

You can drive the same units from a wall switch, a handheld remote or a home system, so closing everything as you leave is one button rather than a walk round the house with a pole. A closed, locked rooflight is the secure state, and making that state easy to reach is half the point of going electric. Sensors and remote closing are standard on the mains-wired and solar-powered units we fit, and they are worth specifying rather than treating as an extra. The detail on those units sits on our electric skylight installation page.

Security for any rooflight is decided by height and access before it is decided by the unit. A rooflight on a two-storey pitched roof is not a burglary route, open or shut, because getting to it means getting onto the roof in full view. The units that deserve thought are the low and reachable ones.

• Flat-roof extensions whose roof can be reached from a garden wall, a lean-to, an oil tank or a bin store. A rooflight here sits at head height once someone is on the flat roof, so it should be treated like a ground-floor window.
• Rooflights below 1.7m on a low outrigger or a single-storey side return, where a person on the ground is close to the glass.
• Walk-on and sunken units at terrace or balcony level, which are accessible by design.

For any of these, the answer is to specify up, not to leave the unit manual. Laminated inner glass holds together if it is struck and resists being pushed through, which is the single most useful upgrade on a reachable rooflight. Multi-point locking on the closed sash resists levering. Restricted opening keeps the vent gap too small to climb through even when the unit is left open. None of that changes the look of the rooflight from inside.

Work through these before you order, and more so if the rooflight is on a reachable flat roof:

• Laminated inner pane on any unit below about three metres or reachable from an adjoining roof. Ask for it by name.
• Multi-point locking on the sash, not motor hold alone, so the closed unit resists levering.
• A restricted vent stop, so the day-to-day opening is a gap rather than a swing.
• A rain sensor and remote or switched closing, so nothing is left open by accident and shutting the house is one action.
• Part K safety glazing where the glass is within reach from inside, which is a regulation, not an upsell.

It is worth separating two things people run together. An electric rooflight is not a security problem because it opens: it is more controlled open than a manual one, and it closes itself in the rain. The question that actually matters is where it sits and how easily the roof can be reached, and that is answered with laminated glass, proper locking and a sensible opening limit rather than by avoiding electric units.

If you are weighing up an opening rooflight on a low or reachable roof and want the glass and locking specified to match the position, tell us where the unit sits and how the roof is reached. Ring 01702 898232 or request a quote, and we will look at the height and access first and the unit second. For the wider picture on running costs and daylight, our skylight installation costs page sets out where an electric unit lands against a manual one.