A villain does not want to be seen. He wants to enter you building as quickly as possible, one good kick at the door lock and the door is opened. He will enter and close the door behind him so that even if you had heard A noise there would be nothing to see!!!

So, fit two locks, spread apart, as a minimum. Ideally a 5 lever Mortise dead lock and a 'yale' type lock.

Make sure that you have good window locks, ERA SNAP to LOCK are the best as you do not need a key to lock them closed i.e. when you close the window the lock operates automatically.

And have an Intruder Alarm System with a good internal sounder on your alarm system so that they cannot hear if you are in the building or if people are coming to see what the noise is about.

Make sure that your system is maintained on a regular basis because your best line of outside defence is your neighbours, IF YOUR ALARM KEEPS ON ACTIVATING THEY WILL LEARN TO IGNORE IT!!!!!!!!!