Window Hinge Types

Quick note if you have sash windows: traditional sliding sash windows don't use hinges at all — they run on cords, weights and pulleys. If your window slides up and down rather than swinging open, see what is a sash window instead. This guide covers casement windows, which open on hinges.

A casement window's hinges do more work than most people realise. They carry the full weight of a glazed timber sash every time it opens, hold it steady against wind, and determine whether you can reach the outside face of the glass to clean it. Get the hinge wrong and the window drops, binds against the frame, or won't stay where you put it — problems that look like joinery faults but are almost always hardware.

Two types account for nearly every timber casement in the UK: friction hinges and butt hinges. They work differently enough that swapping one for the other changes how the window behaves.

Friction Hinge vs Butt Hinge: The Short Answer

A friction hinge is a single engineered unit: a sliding track fixed to the frame with pivoting arms linking to the sash. Adjustable friction inside the mechanism holds the window at any angle without extra hardware. A butt hinge is the traditional pair of leaves joined by a knuckle and pin — it lets the sash pivot, and nothing more. To hold a butt-hinged casement open you need a separate casement stay.

Side-by-Side Comparison

Standards Worth Knowing

Quality window hinges are tested and graded rather than simply sold by size:

• BS EN 1935 — the European standard for hinges, covering durability cycles, load capacity, corrosion resistance and, where relevant, suitability for fire doors.
• PAS 24 — the enhanced security standard for windows and doors. Hinges form part of a tested assembly, so hardware and window are certified together rather than separately. This matters for insurance and for new-build compliance.
• Corrosion grading — salt-spray tested finishes are worth specifying on exposed or coastal elevations, where standard finishes pit and stiffen.

Other Window Hinge Types

Beyond the two main families, several variants solve specific problems:

• Easy-clean friction hinge — opens a gap between sash and frame on the hinge side so the outer face of the glass can be reached from inside. Common above ground-floor level.
• Egress (fire escape) hinge — swings the sash clear of the frame to give the wider unobstructed opening needed where a window serves as an escape route.
• Parliament hinge — projects the sash well clear of the frame or reveal, letting it open back through nearly 180°. Useful on deep reveals and shuttered openings.
• Cranked hinge — an offset leaf that clears a deep rebate or an applied moulding the sash would otherwise foul.
• Rising butt hinge — lifts the sash slightly as it opens, clearing a sill or floor covering.
• Flag hinge — the two halves lift apart, so the sash can be removed without unscrewing anything. Convenient for maintenance and reglazing.

Worth adding here: on upper-floor windows, hinges are often paired with a restrictor that limits how far the sash opens, for child safety. Restrictors and egress requirements pull in opposite directions, so where a window is both above ground level and an escape route, a releasable restrictor is the usual answer.

You don't need new windows to fix a hinge problem. If a casement has dropped, binds on the frame, won't stay open, or has seized after years of paint build-up, replacing the hardware is usually a straightforward job that restores the window to working order for a fraction of the cost of replacement.

We survey the sash, weigh the specification against what's actually on the window, and fit hardware rated properly for it. Where the timber around the hinge has decayed — common on older casements, since the rebate traps water — we splice in new sections before refitting, rather than screwing fresh hardware into soft wood where it will pull out again.

Hinge work is often done alongside timber window repair and draught-proofing, since the window is already open and accessible. If you're unsure whether the problem is hardware or joinery, send us a photo of the window open and we'll tell you which it is.