Window Locks
An unlocked or poorly secured window is the quiet way into a property — and most home insurance policies expect key-operated locks on every window someone could reach. Knightsbridge Locksmiths supplies, fits and repairs window locks of every type, from period sash fittings to modern uPVC handles, for homes and businesses across Knightsbridge and London.
The Window Problems We're Called To
Windows fail security in quiet ways — a handle that no longer locks, a sash that lifts open, or a letter from your insurer asking for locks you haven't got. Tell us the window type and what it's doing, and we'll turn up with the right fittings the first time.
No Lock At All
Reachable windows held by nothing more than a latch. We fit key-operated locks that satisfy insurers and stop the window being opened from outside.
Handle Won't Lock
uPVC and aluminium key-locking handles that spin, jam or no longer hold — repaired or replaced so they lock firmly again.
Sash Slides Open
Sliding sash windows that lift with a push. Sash stops, dual screws and restrictors fitted to hold them shut and safe.
One Team for Every Window in the Property
Timber sashes, uPVC casements, steel Crittall frames — the same engineer measures, fits and tests, with the price agreed before we travel and the fittings named on the invoice you get after.
Locks That Actually Satisfy Your Policy
Fitting a lock that doesn't meet what your insurer specifies can leave a claim disputed. We match the fitting to the window and to the wording in your policy, so a locked window is genuinely covered as well as secure.
Key-operated where it counts
Reachable windows given key-lockable fittings — the standard most home policies require.
Right fitting for the frame
Timber, uPVC, aluminium and steel windows each take a different lock, matched rather than forced.
Child-safe restrictors
Restrictors and sash stops that let a window vent without opening wide enough to be a hazard.
Discreet on period glass
Fittings chosen to sit sympathetically on original sash and casement windows.
Why Knightsbridge Trusts the Job to Us
Advice before a sale
We tell you which windows actually need locking and which don't, rather than pricing up the whole house.
One visit, measured on site
Fittings sized against your windows in person, so nothing is guessed and nothing left half-done.
Insurance-aware
We know what UK home policies ask for on accessible windows, and fit to meet it.
Local to SW1, SW3 and SW7
Run from Montpelier Street, so callouts across Knightsbridge and its neighbours are quick.
How a Window Lock Job Runs
- Tell us the windows
How many, what type, and whether it's security, insurance or child safety driving it.
- Survey and recommend
We check each window and advise which fittings suit it — and which windows genuinely need them.
- Priced up front
Supply and fit quoted before we start, per window, with nothing added afterwards.
- Fitted and tested
Each lock fitted, operated and handed over working, with keys and how-to explained.
Window Security, Neighbourhood by Neighbourhood
Window types vary a lot across Central London — here's what our window lock work tends to involve in four of the areas we're called to most.
Window Locks Knightsbridge (SW7)
Mansion flats around Trevor Square keep their original timber sashes, which look right but rarely lock. We fit discreet sash stops and dual screws that hold them shut without spoiling the joinery.
Window Locks Chelsea & Belgravia (SW3 / SW1X)
Ground-floor shops and offices off King's Road need reachable windows locked to keep insurers and staff happy. We fit key-operated locks that meet policy wording and stand up to daily use.
Window Locks South Kensington (SW7)
Garden-level conversions around Cornwall Gardens have low, reachable windows that make an easy target. Restrictors and key locks keep them secure while still letting them open to vent.
Window Locks Pimlico & Belgravia (SW1P / SW1E)
Family homes around Warwick Way often want windows that lock for security but still open safely for children. We fit restrictors and sash stops that manage both at once.
Where We Fit Window Locks
From 4 Montpelier Street in SW7 we cover Knightsbridge, Belgravia, South Kensington and Chelsea for window security, with wider reach across the SW1 postcodes and central London. A single stuck sash or a full house of windows, the callout works the same.
Knightsbridge & Belgravia
- Montpelier Street
- Trevor Square
- Lowndes Square
- Wilton Place
- Motcomb Street
South Kensington
- Harrington Road
- Cornwall Gardens
- Stanhope Gardens
- Elvaston Place
Chelsea & Brompton
- Egerton Gardens
- Yeoman's Row
- Hasker Street
- Milner Street
One window or the whole property, the routine holds: check what each frame needs, fit locks that suit it, and leave every window secure and easy to use.
FAQs — Window Locks
Do I legally need locks on my windows?
There's no law requiring them, but most home insurance policies ask for key-operated locks on accessible windows, and a claim can be refused without them.
Which windows count as "accessible"?
Broadly, any that can be reached without a ladder — ground floor, basement, and anything near a flat roof, drainpipe or balcony.
Can you lock old sash windows?
Yes. Sash stops, dual screws and acorn fasteners secure timber sashes discreetly, and can be removed later without a trace.
My uPVC window handle won't lock — is that repairable?
Often. A key-locking handle, or the gearbox behind it, can be replaced without changing the whole window.
Will locked windows still open for ventilation?
Yes — restrictors and stops let a window open a safe amount and then lock, so you can air a room without leaving it exposed.
Can you do a whole house in one visit?
Usually. We survey every window, advise which need locking, and fit them in a single appointment wherever we can.