Multi-point locking for windows — when you actually need it

A single locking handle pulls the sash tight at one point. On a small window that is enough. As the sash gets taller, the corners furthest from the lock lift off the gasket — the window whistles, leaks and can be levered open.

What multi-point locking does

An espagnolette runs a locking bar up and down the sash from the handle. Cams or mushroom pins along the bar engage keeps on the frame, pulling the whole sash evenly onto the gasket. You get a better seal, less rattle, and real resistance to forcing.

When to specify it

• Any openable sash taller than about 1.2 m.
• West and south elevations that take driving rain.
• Ground-floor and accessible windows for security.
• Anything the client wants to feel solid — it is the single biggest change to how a window “shuts”.

Mushroom cams vs standard cams

Mushroom-headed cams pull into a shaped keep and resist the sash being jemmied away from the frame. Standard roller cams seal well but give less security. For ground floor and apartments, specify mushroom cams and matching keeps.

Getting the parts to match

The gearbox backset (handle spindle to the sash edge) and the bar pitch have to match the profile. Corner drives carry the locking action around to the head and cill. Order the gearbox, extension bars, corner drives and keeps as one set for the sash size — mixing brands rarely lines up.

Give us the sash height and width, the profile system and the exposure, and we will build the locking set from stock.