The Crime Prevention Website


Minimum security requirements

The majority of these doors are located in the front elevation of a house (the best place for home security purposes) but can be on the side.  The following bullet points indicate the minimum security requirements for a timber door that should satisfy your insurance company’s requirements, but you must check with them first.

  • The door should preferably have a solid core construction that is a minimum 44m thick to allow for the installation of mortice locks and to provide resistance against forcing
  • It should be hung on three hinges
  • The frame should be secured to the brick or block with screws or frame fixers at maximum centres of 600mm and within 300mm from each corner.  You may not be able to identify the fixing points on an old door frame.
  • The door should be fitted with two locks: An automatic deadlocking rim nightlatch certificated to BS 3621 positioned about one third down from the top of the door, which you would use for opening and closing the door.  A mortice deadlock certificated to BS 3621 positioned about one third up from the bottom of the door, which you use at night and when you go out.
  • A pair of hinge bolts should be fitted if the door opens outwards (which is unusual)
  • A door limiter or door chain might be useful, but see Door chains and limiters in  Door locks, hardware and fittings
  • Fit a door viewer if you do not have clear glass in the door
  • A letter plate deflector (or hood) to prevent access to the turn knob on the back of the rim lock.

Additional security measures

The following additional security measures can be added if you live in an area with crime risks higher than the average.

  • A security grille can be fitted to the back of a glazed panel to prevent a glass breaker accessing the rim lock (normally only required if the front door is deeply recessed)
  • Ordinary glass in a glazed panel can be replaced with 6.4mm or thicker laminated glass
  • Reinforcing bars can be fitted on the inner face of the hinge and locking frames (Known as Birmingham and London Bars respectively)
  • Reinforcing plates can be fitted on either side of the mortice lock