The most suitable option is the reliable PVC doors with a good locking mechanism. Particular attention should be paid not to the external finish, but by a metal basis, which is the main element of the door. It is on its quality that the safety of housing depends. It is very important to ensure that the locks are installed at once several types. The reason is simple — many attackers can hack only standard locks, and if 2 locks of different types are installed on the door at once, then the task is very complicated.