The Crime Prevention Website


These timber doors are made to various designs; some with a single pane of glass in each door leaf and others with perhaps twelve panes or more.  In my experience of visiting many scenes of burglary it tends to be the four or six paned leaf design that is more at risk.  A bottom pane of glass can be kicked or cut out leaving a big enough hole to crawl through.  Very often the glass will fall onto a carpet limiting the noise. Ones with one pane of glass present a percieved risk of injury to the thief should he try and smash the glass and the ones with lots of little panes are simply much more difficult to kick in.  As the purpose of French doors is to allow plenty of sunlight to come into the room most people would not want to cover the lower panes of glass with plywood panels and so the security solutions for this type of door will be a little different from what has been said about single leaf back and side doors.  In addition, these doors simply have to be locked correctly, because if the second opening leaf is at all suspect they can be easy to force.

Modern panelled doors often use one large double glazed seal unit and the glazing bars will be glued onto the surface of the glass giving the appearance of a multi paned door.  Others will incorporate a framework between the two sheets of glass to give a similar effect.  The glass used in these versions is likely to be toughened glass that has no security value. (See  Glazing for domestic security   to see how to make improvements) 

Minimum security requirements

The following bullet points indicate the minimum security requirements for a double leaf timber door that should satisfy your insurance company’s requirements, but you must check with them first.

  • The door leaves should be at least 44mm thick to allow for the installation of mortice locks and to provide resistance against forcing
  • Each leaf 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 first opening leaf should be fitted with a mortice sashlock certificated to BS 3621 (possibly a rebated type) positioned near to the centre of the door leaf and a pair of key operated mortice security bolts fitted into the top and bottom rails
  • The second opening leaf should be fitted with a pair of key operated mortice security bolts into the top and bottom rails
  • If the top and bottom rails of the door leaves are very small you may have to fit pairs of press bolts instead, so not to weaken the door
  • If the second opening leaf has been fitted with finger operated espagnolette bolts (in the rebate of the leading edge of the leaf) you won’t need to fit mortice security bolts or press bolts, as these bolts will be covered by the first opening leaf when closed and, providing they are operating efficiently, should provide sufficient security
  • A pair of hinge bolts should be fitted to each leaf if the door opens outwards; and most do

Additional security measures

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