Which Smart Lock Fits My Door? uPVC, Composite & Mortise Guide
Before you buy any smart lock, you need to know which kind of lock your door already has. UK and European front doors use three main types, and each needs a different kind of smart lock. Here's how to tell them apart in under a minute.
Step 1: lift the handle
The three door types
Mortise sashlock
A lever handle on a long backplate, with a key cylinder below it. One lock body sits inside the edge of the door. Common on timber, steel and aluminium doors across the UK, the Netherlands and Belgium.
Grisoll fit: VANTA, ATLAS, JUNO, JUNO+ and AURA, if your centre distance is 85mm.
Multipoint (uPVC and composite)
Lift-to-lock handles on a long plate. A gearbox in the door edge drives bolts, hooks or rollers at several points. Standard on UK uPVC and composite doors.
Grisoll fit: talk to us first. Don't remove your multipoint mechanism to fit a single-point lock.
Round bore latch and deadbolt
A round knob or lever, often with a separate deadbolt above it, fitted in round 54mm holes through the door. Common on internal, garage and some back doors.
Grisoll fit: NOVA smart lever lock or LYRA smart deadbolt.
Step 2: measure three things
- Door thickness: front to back, in millimetres.
- Backset: from the edge of the door to the centre of the key cylinder.
- Centre distance: from the centre of the handle spindle to the centre of the key cylinder. Grisoll mortise locks use 85mm. Many German, Dutch and Belgian doors use 72mm, and many UK multipoint gearboxes use 92mm.
Our Find Your Fit page has a diagram and a 2-minute quiz that matches your answers to the right lock.
Smart locks for uPVC and composite doors
Multipoint doors are the hardest doors to make smart, because the handle has to be lifted to throw the bolts. There are two main routes:
- A retrofit smart lock over your euro cylinder. You still lift the handle yourself, then the smart lock turns the key. Your multipoint locking stays as it is.
- A dedicated multipoint smart handle made for your gearbox's centre distance, which replaces the handles but keeps the multipoint mechanism.
Whatever you choose, keep the multipoint mechanism. It's a big part of your door's security, and many insurers expect it.
If you'd like to know whether a Grisoll lock can work with your multipoint door, email photos of the handle plate, the door edge and the gearbox (the metal strip along the edge) to info@grisoll.com. We'll give you an honest answer. If it isn't a good match, we'll tell you.
A note on insurance
Some UK home insurance policies require locks that meet a particular standard, such as BS3621 for mortice deadlocks or TS007 for euro cylinder doors. Check your policy wording, or ask your insurer, before changing any lock. Keep your original lock in case you ever need to refit it.