Mortice or sash-type locks (those embedded within a door) offer more security than rim-type locks (those attached to the surface of the door).
5-lever locks are recommended; they have over 1,000 key options, making it unlikely that a duplicate key can be used.
Fitted locks used to secure doors, gates and shutters should conform to BS 3621: 2007+A2: 2011
Padlocks can be open or closed shackle. ‘Open’ refers to the substantial gap between the centre of the shackle and the body of the padlock. It is possible to prise open the shackle with a crowbar or pair of bolt croppers. On a closed shackle the space between the shackle and padlock body is much smaller, making it difficult to prise open.
When securing doors or pairs of doors, a padlock may be used in conjunction with a locking bar or pad bar. These can be horizontal or vertical and should be securely bolted to wooden doors or alternatively welded to metal doors.
Padlocks used to secure such fittings should conform to BS EN 12320:2012 or equivalent.
Padlocks with concealed shackles or raised ‘shoulders’ are recommended since they offer greater resistance to attack. For added security, padlocks can be shrouded to prevent attack using leverage or cutting tools.
Always ensure keys are accounted for and that they are stored securely when not in use.
Do not leave a spare key in a convenient hiding place. It is better to leave a spare set of keys with a neighbour; you could offer to do the same for them.