Most home insurance policies set minimum security conditions. If your locks do not meet them and you are burgled, a claim can be reduced or refused. The wording varies between insurers, so the first step is always to read your own policy, usually under a heading like minimum security requirements. This guide explains the terms you will meet there.
Timber doors: five-lever mortice locks to BS 3621
The standard most policies name for a timber final exit door is BS 3621. It covers mortice deadlocks and sashlocks that resist drilling, picking and forcing, and that have at least a thousand key differs. A lock that meets it carries the BSI Kitemark and the number BS 3621 on the faceplate. A five-lever lock that is not marked BS 3621 is not the same thing, even if the box says five lever.
There are two related standards. BS 8621 is for locks that need a key outside but can be opened from inside without one, which some flats use for escape. BS 10621 is for locks that can be set from outside so they cannot be opened from inside, used on some commercial doors. Which one applies depends on how the door is used.
uPVC and composite doors: multipoint locks and the cylinder
Most modern plastic and composite doors have a multipoint lock that throws several bolts along the edge when you lift the handle. The weak point is often the euro cylinder, the barrel the key goes into. If the cylinder sticks out from the handle it can be snapped with simple tools, and the door opens. Lock snapping has been a common method of entry for years.
The answer is an anti-snap cylinder. Look for one of two marks. TS 007 is a Kitemark scheme with a star rating: a three-star cylinder on its own, or a one-star cylinder with two-star security handles, is what insurers and the police initiative Secured by Design look for. Sold Secure SS312 Diamond is an equivalent rating from the Master Locksmiths Association test house. Either is widely accepted, but check your policy wording.
Replacing a cylinder is a quick job and does not mean replacing the door or the multipoint lock. Measure or bring the old cylinder, or ask a locksmith to size it. A cylinder that is too long sticks out and undoes the benefit.
Patio, french and bi-fold doors
Sliding patio doors should have a lock at the top and bottom, or anti-lift devices, so the panel cannot be lifted out of its track. French doors need bolts into the frame at top and bottom of the first-closing leaf as well as a proper lock on the second. Many policies ask for key-operated locks on all these doors.
Windows
Insurers usually ask for key-operated locks on all ground floor windows and any that can be reached from a flat roof, a porch or a drainpipe. Modern windows often have them built into the handle. Older timber windows can be fitted with surface-mounted locks. Restrictors are useful for ventilation but are not a substitute for a lock.
Doorsets and the PAS 24 label
If you are replacing a whole door rather than a lock, look for PAS 24. It is a test of the complete doorset, frame, leaf, hardware and glazing, against attack. New-build homes have had to meet it for years and insurers recognise it. A PAS 24 door still needs to be fitted correctly to perform.
What to do with this
Read the policy. Walk round the house and look at each door and window against it. If anything is unmarked or you are not sure, a locksmith can tell you in a few minutes what you have and what, if anything, needs changing. Keep the receipts for any upgrade with your policy documents, and tell your insurer if they asked you to make a change.