Customers quite often ask me what the best lock would be. However, quite often we are standing next to a door that the big, bad wolf wouldn’t even have to huff over — one small puff and it would be open.
The physical strength of the the door and frame are just as important as the lock. This is especially true around here (London) where nearly all break-ins I attend are literally that: smashing the door in.
A solid door is better than a hollow door or a panelled door. Raised moldings can make it look nicer; panels simply make it easier to burst through. If you must have panels — of wood or of glass — you really need to consider a mesh or a grille on the inside. If grilles or meshes over panels are aesthetically unacceptable then you need to consider a monitored alarm or a big dog.
I’m sometimes asked to fit another mortice deadlock, but in a door that’s too thin or too insubstantial. I’m afraid that cutting a big hole in a door that’s less than 44 mm thick, or that’s hollow, simply makes it easier to burst open.
Are the door or frame cracked or split, especially around the locks and their keeps? Minor cracks and splits can be dealt with via strengthening plates and bars. Major cracks or splits really require the attention of a good carpenter.