Traditional sash and case windows use several different fittings. Some simply hold the meeting rails together; others limit how far a sash opens or add key-operated security. The best choice depends on the condition of the window, the timber, the existing ironmongery and how the room is used.
Choosing the right sash window lock
Our guidance focuses on traditional timber sliding sash and case windows, rather than assuming every modern window security fitting will work on a heritage sash.
Common types of sash window locks
Meeting-rail fasteners, keyed sash locks, sash stops and opening restrictors perform different jobs. A fastener pulls the two meeting rails together; a stop or restrictor limits movement. Choose fittings based on the window construction rather than the product name alone.
What to look for when buying
Measure the meeting rails and available timber, check the screw positions, confirm whether the fitting is handed, and consider the finish. For period properties, sympathetic brass or bronze-style ironmongery may suit the existing appearance.
Can you add a lock without replacing the window?
Often yes. Sound timber sash windows can commonly accept compatible replacement fasteners or additional locks. Where the timber is split, rotten or out of alignment, repairs may be needed before fitting new hardware.
Security, ventilation and escape
Avoid fitting restrictions that interfere with required escape windows or safe operation. For households with children, consider suitable opening restrictors and obtain professional advice on compatibility.
Related sash window lock guides
Related sash and case window services
Explore our sash and case window repairs in Stirling, window restoration, sash cord replacement and draught proofing.
Frequently asked questions
Can I fit new locks to old sash windows?
Often, provided the timber is sound and the hardware suits the sash design. Check alignment, clearances and any heritage constraints first.
Will a replacement fastener make my sash window secure?
A meeting-rail fastener mainly holds the sashes together. Additional security may require appropriate locking hardware and repairs to the window itself.
Do you supply and fit sash window locks?
Contact us to discuss inspection, repairs and suitable replacement fittings for timber sash and case windows. Online product sales are not yet available.
Need advice about a sash window lock? Contact The Sash & Case Window Company for an assessment or quotation.
