Are Roof Windows Secure?

How reachable is the window?

Security begins with access. A roof window on the main slope of a two-storey house is far from the ground and needs a ladder to reach, which is noisy and visible. A burglar would pick an easier route. The picture changes if the window sits above a single-storey extension, a porch, a garage roof or a flat roof, where someone can step up from a wall or a water butt. Those are the windows to treat as ground-floor windows for security.

Look at your own house from the outside. If you can see an easy climb to a roof window, then so can anyone else. Trimming back climbing plants, moving water butts and bins away from walls, and thinking about the neighbours' sheds all reduce the risk.

Locks and handles

Modern roof windows have a locking mechanism built into the handle or the frame, often a multi-point lock that holds the sash at more than one position. A key-operated version suits a window in a child's room or a rented property. Check that the key works and the lock engages firmly, and that the handle does not wobble. On an older window, the catch can be worn or the frame distorted, which weakens the hold.

Some windows have a ventilation setting, in which the sash opens a few centimetres and locks there. This allows air in without leaving the window fully open, but check that the vent position is genuinely lockable and not just a stop. Windows left on a loose vent overnight, or opened by a pole and forgotten, are the usual way a roof window is compromised. Our answer on electric roof windows covers motorised models that can close by remote.

Glass and frames

The glass is the next question. Standard roof windows are double glazed with toughened or laminated panes. Laminated glass has a plastic interlayer that holds the pane together when struck, so it cracks without letting a hand through. It is the better choice for a window at risk, as well as being quieter in rain. The frame itself is timber, pine with a polyurethane coating, or aluminium-clad, and is built to be stiff.

Flat rooflights are another matter. Single-skin polycarbonate domes and lightweight units on a flat roof can be lifted or broken more easily, and some have hinged lids that a thief can force. Glazed units with a proper kerb and a lock are stronger. The guide on flat roof rooflights explains the types.

Escape and security together

There is a tension between security and escape. A roof window in a loft bedroom may be the way out in a fire, and it must be possible to open it quickly from inside without a key being hunted for. A roof window only counts as an escape window for storeys within 4.5 m of the ground, and the page on escape roof windows sets out what is expected. A key lock on an escape window should have the key kept close, and some designs allow a thumb-turn on the inside.

Simple habits that help

Security is partly routine. Close and lock roof windows when you go out and at night unless the vent setting is lockable. Keep the key for a keyed lock somewhere sensible, not on a hook below the window. Do not leave a ladder or tall furniture where it gives access to an upper window. A light and a visible alarm sensor deter a casual attempt, and a neighbour who keeps an eye on the house while you are away helps more than any lock.

Blinds help too. A blind in the closed position hides the room from anyone looking in from a neighbouring roof or a higher building, and a dark room beneath a window gives little away.

Water as well as people

Security also means keeping the weather out. A window that has been forced or left on vent in a storm can let rain in, and a flooded loft is not a small insurance problem. The seals and the flashing are the other half of the job, and a window that is sound against people but leaks at the flashing is not secure in any useful sense. A yearly check of the seals, the handle and the glass is cheap protection.

Insurance and what to ask

Insurers sometimes ask about window locks, and those on accessible windows may be a condition of cover. Read your policy wording. After a window is fitted, keep the paperwork and the keys, and note the make and model in case you need to replace parts.

When we survey a roof window job, we look at how reachable the opening is and suggest laminated glass and a locking handle where the window is exposed. The installation is described in our fixed written quote, with the glazing specification listed. See the main roof windows and skylights page for the full service.