Fit window restrictors

Fit window restrictors to stop windows opening too far, using screws suited to your frame material.

WR-01Pick the right restrictor for your windowChoose a restrictor rated for your window style (casement, sash or tilt-and-turn) and for the job you need it to do. If the window is a designated fire escape (usually a bedroom window), buy a quick-release type so it can still open fully in an emergency.

RULES

1 each · Window restrictor kit (cable or hinge type)

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KNOW THE RULES

Building Regulations require at least one window per bedroom to open fully as an escape route. Never fit a permanent, non-release restrictor to that window.

WR-02Gather your toolsYou'll need a drill/driver, a small bradawl or pilot bit, a screwdriver, a pencil, masking tape and safety glasses. Check the restrictor's fitting instructions for the exact screw size it comes with, as kits vary.

1 each · Cordless drill/driver

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1 each · Safety glasses

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1 each · Bradawl

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WR-03Work out what your frame is made ofYou're fixing into the window frame here, not the wall, so studs and masonry don't come into it. Look and tap: uPVC feels light and slightly hollow with a plastic sound; aluminium is thin, cold and rings when tapped; timber shows a grain and feels warm; old steel (Crittall) frames are heavy and a magnet will stick to them. A test pilot hole confirms it — white plastic dust means uPVC, pale shavings mean timber, and bright metal swarf means aluminium or steel.

WR-04Mark and mask the fixing pointsHold the restrictor's frame plate in position, following the maker's template, and mark the screw holes with a pencil. On uPVC or aluminium, stick a strip of masking tape over each mark first — it stops the drill bit skating on the smooth surface and reduces the chance of cracking.

1 roll · Masking tape

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WR-05Drill pilot holes to suit your frameFor uPVC, drill a 2-3mm pilot hole about 15mm deep — go slowly, as uPVC frames have a steel reinforcing bar inside and you may need to nudge the position slightly if you hit it. For timber, drill a 2mm pilot hole slightly shorter than the screw. For aluminium, use a 2mm pilot and drill steadily to avoid cracking the metal.

1 set · Pilot drill bit set (2-4mm)

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WR-06Fix the frame plateUse self-tapping screws for uPVC or aluminium frames, and ordinary wood screws for timber frames — the kit usually supplies the right ones. Drive them by hand or on a low driver setting; overtightening can crack uPVC or strip a thin aluminium frame. Keep the fixing at least 15mm from the glass edge so you don't risk the sealed unit.

1 pack · Self-tapping screws No.6 x 25mm (pack)

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1 pack · Wood screws No.6 x 25mm (pack)

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WR-07Fit the sash plate and connect the restrictorOpen the window slightly and mark, then drill and fix the second plate on the opening sash, using the same pilot hole size and screw type as the frame. Attach the cable, arm or hinge stay between the two plates as shown in the kit instructions.

WR-08Check the restricted opening gapClose the window fully, then open it against the restrictor and measure the gap. For child safety, upper-floor and easily accessible windows should open no more than 100mm unless the restrictor has a quick-release catch for use as a fire escape.

WR-09Test the release actionIf you fitted a quick-release restrictor, test the catch or key several times to make sure it disengages easily — everyone in the household should be able to operate it in the dark without a key if it's an escape window. If it's a fixed restrictor with no release, confirm it holds firm when you push on the open sash.

WR-10Tidy upPeel off the masking tape and wipe down the frame with a damp cloth to remove dust or swarf. Vacuum any plastic or metal shavings from the sill and floor before they get trodden in.

1 each · Cleaning cloth

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