Window Locks Fitted Across South London
Key-operated window locks on uPVC, timber and aluminium frames — sash, casement, tilt-and-turn. BS 7950 insurance-grade hardware, fixed written quote before we drill a hole, spec sheet on completion for your policy file.
At-a-glance — what you get
Fixed written quote before we drill
30 min
Avg response time
5.0 ★
155 Google reviews
A window lock is what keeps your home insurance valid
Almost every UK home insurance policy has the same clause buried on page 14: “All ground-floor and easily accessible windows must be fitted with key-operated locks.” Miss one, and a burglary claim can be denied outright — even if the intruder came in through a different window.
We fit key-operated window locks across South London in a day. The survey takes 15 minutes: we walk the elevations, note which windows are ground-floor, easily accessible (drainpipe, flat roof, bin store, extension), and which frame type each one is — uPVC, timber, aluminium. Then we quote one fixed price for the lot.
This isn't a premium-lock upsell. A key-operated window lock on a standard uPVC casement is about as minimal as UK security gets. What matters is which windows, how many, and what standard. Get that right and your insurer can't refuse. Get it wrong and you're paying your premium for nothing.
Most London burglaries — roughly one in three according to Metropolitan Police data — enter through windows, not doors. The overwhelming majority of those are through unlocked or un-lockable windows. Fitting locks is the single cheapest security upgrade with the biggest insurance benefit. See our insurance-approved door locks page for the door-side counterpart.
Five window types — five different lock jobs
Every window has a lock pattern it was designed for. Fitting the wrong unit — or bolting something on that doesn't match — gets you a seized window, voided warranty, or worse: your insurer refusing your next claim.
uPVC Casement
Modern hinged window that swings outward. The handle drives an espag (espagnolette) rod with shootbolts top and bottom.
- Key-lockable handle replacement
- Shootbolt gearbox upgrade if old
- Ventilation stop catch as option
Timber Sliding Sash
Victorian/Edwardian terraces. Two sashes that slide vertically — the upper sash drops, the lower rises. Weakness: the meeting-rail gap where burglars lift the lower sash.
- Fitch lock or sash stop key lock
- Dual screws top + bottom
- Ventilation-position safe stop
uPVC Tilt-and-Turn
Handle at 90° tilts the top for ventilation; at 180° swings the whole window inward. Continental system — very common on new-build extensions.
- Key-lock handle (3-position)
- MACO or Mila multi-point gearbox
- Restrictor hinge adds child safety
Aluminium Slim-Profile
Narrow-style frame found on older flats, commercial conversions and 70s-80s shopfronts. Needs slim-profile locks — standard uPVC locks will not fit.
- Narrow-profile espag lock
- Rebated shootbolt for thin rail
- Secondary swing-bar lock option
Timber Side-Hung Casement
Solid wood casement, usually in older 1930s-1950s houses or conservation areas. Needs screw-on locks that don't rely on a multipoint rod.
- Key-operated cockspur replacement
- Surface-mount fitch lock
- Swing lock for fanlight stays
Crittall Steel-Framed
Period steel-frame windows, especially on 1930s suburban homes and converted warehouses. Gently does it — wrong hardware cracks old galvanising.
- Purpose-made steel-frame key lock
- Heritage-appropriate finish
- Peg lock option for fixed lights
Eight window lock jobs — one fitter, one day
From a single stuck sash in a Victorian terrace to a whole-house upgrade before a re-insurance quote. We cover it all, including the boring paperwork your insurer asks for.
Whole-house survey
Walk every elevation, identify accessible windows, photograph each frame type, quote fixed price. Free, no obligation.
uPVC handle replacement
Old non-keyed handle swapped for a key-operated Saracen or Yale. 10 minutes per window, keeps existing espag rod.
Shootbolt gearbox
Worn/stiff multipoint rod replaced end-to-end. Fixes windows that don't close properly into the frame.
Sash window locks
Timber sliding sash fitted with dual screws, fitch lock or sash stop. Heritage finishes for conservation areas.
Ventilation stops
Restrictor catches let you sleep with a window open 100 mm — locked, ventilated, secure. Child-safe.
Jammed / seized windows
Windows that won't close, handles that won't turn, espag rods misaligned. Diagnose + fix in one visit.
Spec sheet for insurer
Full list of each lock model, position, BS/PAS reference, fit date. Print-ready for your policy renewal.
Landlord / HMO package
Multi-property window lock audit + fit. Key-alike across a portfolio. 30-day invoice terms + VAT receipt.
Six situations where window locks are non-negotiable
Every other week we get a call from someone who just realised their insurance clause is sharper than they thought. If one of these is you, book the survey before the renewal lands.
Just moved in — pre-renewal
Insurer's letter arrived. Policy requires key-operated locks on accessible windows. Get it done once, spec sheet goes on the policy file, done forever.
Flat roof below a bedroom
Bathroom extension, garage, conservatory — any flat roof turns an upstairs window into an “accessible window” for insurance purposes. Needs a key lock.
Young children / sleepwalkers
Ventilation stops let a window open only 100 mm — enough for airflow, not enough for a child to fall through. Lockable so no one removes it without a key.
Landlord / HMO renting out
Tenancy agreement plus fire-safety obligations mean lockable windows with keyed egress on bedrooms. We do whole-portfolio fits with key-alike.
Burglary or attempted break-in
Crime-reference number issued, insurer wants upgrades before renewing. Emergency fit the same day. Rescue your renewal.
Conservation area / listed building
Planning officer won't let you change windows. We fit heritage-appropriate sash stops and fitch locks that meet insurance without touching the sightline.
Five steps, whole house in a day
Same proven process for every job. Survey-to-handover in one visit for most properties, two visits only if we need to order a non-standard part.
We walk every side of the house inside and out. Each window gets marked as ground-floor, accessible upper (flat roof / drainpipe) or safe upper (isolated). Frame material noted, existing hardware photographed, insurance policy scanned if you have it to hand.
One sheet: window-by-window list, lock model per window, total price. The price you see is the price you pay. Valid 30 days. You sign or bin it — no pressure, no upsell call-backs later.
Handle screws out, espag rod disengaged, old locks uncoupled. We leave the seal intact — every new lock screws into the same holes or reinforced sections. No drilling through gaskets, no weather-tight failure.
New key-operated handle / sash lock / fitch installed. Each window tested 10 times open-close-lock against the keeps. If the espag rod is tight we adjust the keeps to suit. Keys pre-paired for key-alike across the house.
Printed sheet: every window, lock model, BS or PAS reference, fit date, photo. Two keys per lock + one master. We show you how to lock/unlock from inside and how to release a ventilation stop. Signed off, you email the sheet to your insurer.
Window locks across 30 South London postcodes
Van stock covers all standard uPVC casement and sash window units. Premium or period hardware is ordered next-day. Whole-house fits typically one day, two visits max.
Six things cheap window lock fitters miss
- Whole-elevation survey, not just the front.Insurance needs every accessible window. Cheap fitters do the visible ones; we walk the sides and back where the drainpipes are.
- Written spec sheet for your insurer.Window-by-window list, lock model, BS/PAS reference, fit date. Keeps your policy clean at renewal.
- Key-alike across the whole house.One master key opens every window. We pair keyways on-site so you aren't juggling 8 identical-looking keys on a hook.
- Fire-egress planning on upper floors.Bedroom windows locked but still escapable in a fire. We brief every household member on release procedure before we leave.
- Ventilation stops, not hacky compromise.Key-lockable 100 mm restrictor catches so you can sleep with airflow. Child-safe, burglar-safe, no wedges or sticks needed.
- Seal stays intact.Every fit screws into the frame's reinforced sections or existing mortice. No drilling through gaskets or glass units. Your double glazing stays weather-tight.
The numbers — proof, not fluff
Every stat verifiable on request
Every fit includes
- Free whole-elevation survey with insurance-compliance audit
- BS 7950 / PAS 24-graded hardware from ERA, Yale, MACO, Avocet
- Key-alike across the house at no extra charge
- Ventilation-stop catches on bedroom windows (optional)
- 2 keys per lock + 1 master labelled by window
- Printed insurer spec sheet for your policy file
Three ways to price the job
Every price below includes labour, BS 7950 hardware, keys, and the spec sheet. What changes is how many windows and which frame type.
Option 1
One window. One lock. One visit. Perfect when you've got a specific pre-renewal spot-fix.
- Single frame survey + quote
- BS 7950 hardware included
- 2 keys + 1 master
- Written spec sheet
- 12-month workmanship warranty
Option 2
Standard 3-bed London terrace: 6–10 insurance-accessible windows. One-day fit, key-alike across every window at no extra charge.
- Whole-elevation survey + audit
- Key-alike across all windows
- Mix of uPVC / timber / ali
- Ventilation stops included
- Full spec sheet for insurer
- 12-month workmanship warranty
Option 3
Timber sliding sash, steel Crittall, conservation area, listed building, or multi-unit HMO rollout.
- Send photos on WhatsApp
- Reply within 2 working hours
- Heritage finish options
- Conservation-area compliant
- Invoice + VAT for landlords
Payment: card or cash. No hidden fees: the quote is the price. After midnight: prices increase — call for a quote. The £180 from-price is per window on a standard uPVC casement during working hours. Timber sash, aluminium slim-profile and Crittall steel are quoted individually.
155 Google reviews · 5.0 average
Three recent window-lock customers — real people, real jobs
Got the standard "your policy requires key-operated window locks" letter 10 days before renewal. Walked away from two companies who quoted wildly different prices without even coming to look. These guys did the survey the same afternoon, quoted 9 windows for £310, fitted everything before 3pm the next day. Key-alike, spec sheet, insurer happy. Would hire again for literally any lock job.
Conservation area, Victorian sash windows, nothing can be visible from the street. Another locksmith told me I needed to replace all the windows. These guys fitted fitch locks and sash stops inside the frame — completely invisible from outside, and passed the insurance audit. Proper craftsmanship from someone who actually understood the windows, not just bolting on whatever the van had.
Portfolio of 4 HMOs in Thornton Heath, coming up for insurance renewal. Needed key-alike across all 4 properties so I'm not carrying 48 different keys. They did every window in every property over 2 days, delivered a master-keyed system with 4 property keys + 1 landlord master, plus individual spec sheets per house. Invoice + VAT on 30-day terms. Precisely what I needed.
Window locks — straight answers
Short, honest, no jargon. If we don't know, we say so.
Do I legally need window locks in the UK?
What is BS 7950 and does my lock need it?
Can window locks be fitted to uPVC, aluminium and timber?
How many window locks do I need?
Do window locks weaken the frame or affect double glazing?
Can I fit window locks myself?
Are all my existing window keys compatible?
What about fire egress from upper-floor bedrooms?
How much does window lock fitting cost?
Window & Garage security — keep exploring
Other parts of the house insurers care about just as much.
Window & Garage Hub
All window, garage and shed security categories — the main index page.
Sash Window Locks
Victorian/Edwardian timber sliding sash — the specific lock patterns that work.
Anti-Snap Door Locks
The door-side counterpart. Same insurance requirement, same philosophy.
Insurance-Approved Locks
The full BS/PAS standards primer — doors, windows, everything insurer wants.
Window lock fits across these South London towns
Renewal letter in hand? Book today.
Free whole-house survey, fixed written quote, one-day fit for most properties. Spec sheet for your insurer included — no follow-up paperwork chase.
24/7 emergency locksmith serving South London since 2015 — trusted by homeowners, landlords and businesses across Sutton, Mitcham, Wallington, Cheam, Purley and surrounding areas.