Bolts seem often to be overlooked as a security option. Customers sometimes ask what kind of lock will do such-and-such; and the answer is a £5 bolt.
Whether you call it a barrel bolt or a tower bolt or a shoot bolt (and quite frankly I’m not sure which is the correct term), this
kind of thing, is a cheap, simple and effective way of securing your door at night without actually locking yourself in and creating a fire risk. (You should think very carefully about locking yourself in with a key that you can misplace.)
And if you have children that have reached the age of common sense, you need to think about them being able to reach the bolt.
The size of the bolt pictured above is important. It’s at least 150 mm long (6 inches). And the size of the screws are important as well: say 25 mm (1 inch). A titchy little brass bolt with titchy little screws is a waste of time and money.
The main disadvantage (in common with several other possible solutions) is when there is uncertainty as to when everyone will be home and inside. You don’t want to be locking a house mate or family member out and having them wake you to let them in. If this is the case, then a cylinder operated dead lock with a key on the outside and a thumbturn on the inside is probably the answer.