43 Security CI/SfB (68) UDC: 343.7 Uniclass U547
David Adler The editor acknowledges assistance from the Metropolitan Police Crime Prevention Design Department in updating this chapter
1.01 Crimes The main types of crime are: 1 2 3 4 5 6 7 8 9 10
Pilferage by staff or other insiders Pilferage by public (shoplifting) Vandalism without gain to the perpetrator Casual break-ins Planned break-ins Attacks on persons for immediate gain (muggings, etc) Various types of kidnapping, hijacking, etc, mainly for ransom Bomb attacks, etc, for political objectives Fraud Assaults for other than immediate gain (racism, ‘fun’, vengeance, etc) 11 Arson 12 Motor vehicle crime 13 Anti-social behaviour Table I indicates which particular building types are subject to these crimes and suggests suitable precautionary measures. Most combative measures are designed either to slow up criminals until they feel vulnerable to discovery or else makes it difficult for them to remain unobserved.
1.02 Fences Where commercial or industrial site perimeter protection is indicated a fence is better than a wall as one can see through it. It should be not less than 2.5 m high and topped with two strands of barbed wire. Fences higher than 2 m will require planning approval, and a form of protection such as barbed wire may possibly be the subject of a public liability claim. If a wall has to be used, it should have barred openings in it. In the domestic situation, openings in walls may be inappropriate. Walls and wooden fences can successfully be protected with trellis topping.
1.03 Windows Window panes less than 0.05 m2 in area cannot be climbed through. Larger panes should be as large as possible. Laminate glass may be used, particularly near door locks. For more security windows should be barred or fitted with grilles. Vertical bars are more effective than horizontal. Ideally, the bars should be of square cross-section minimum 20 mm at a maximum spacing of 125 mm and built in 75 mm. Transverse tiebars should be provided at 600 mm centres.
1.04 Front doors The ‘last door out’ (which cannot be barred or bolted from inside) should be as stout as possible, in any case more than 44 mm thick. It should be solid (not of hollow construction) and the hinge should be internal. When opening in, the stop should be formed by rebating the solid and not planted; otherwise the tongue of the lock is readily accessible. The lock should be a mortice lock
to BS 3621: 1963 or equivalent, although some prefer rim locks as mortice locks can weaken a door. If more than one lock is fitted they should be well spaced apart (approximately one third the door height). Fire regulations require door locks to be openable from inside without a key: this conflicts with security as it facilitates an intruder’s escape. In cases when there are more than a few people inside the building, or where the occupiers are unfamiliar with it, the fire escape requirements are paramount. This does not generally apply to most small domestic premises, where it is usually possible to secrete a key in proximity to the door. Locks that are key lockable from outside but have no keyhole inside and are not unlockable in any other way should not be used as legitimate occupiers may be inadvertently locked in. Security experts also recommend non-key-operated bolts and chains in addition to locks. The disadvantage of these is that a successful intruder will use them to avoid being interrupted. However, such an interruption may lead to violence; the balance of opinion favours their provision and use. A letter plate in the door should be sized and positioned so that it cannot be used to gain entrance: the minimum distance between it and the lock should be more than 400 mm. There have been disquieting examples of arson using letter boxes. Consideration may be given to to the provision of a letter box separate from the house on the Continental pattern. Unless there is another method of identifying callers, a lensed spyhole should be provided. Glass in doors or adjacent to them should be laminated. 1.05 Other doors All external doors should be of similar construction to front doors. Doors that are outward opening should be fitted with hinge-side bolts to prevent ingress by hinge removal. Patio doors are particularly vulnerable, and a supplementary steel roller-shutter may be necessary. Other than this, ensure minimum three-point locking, an anti-lift device and laminated glass in the outside layer of sealed units. French windows may also need supplementary shutters, but espagnolette locking bolts are a minimum requirement, on each leaf if double. Doors from integral garages should be as secure as external doors. Other internal doors are best left unlocked to avoid unnecessary damage. 1.06 Defensible space The layout of any site, industrial, commercial, residential or otherwise should be considered from a security point of view. If possible, ensure that all normal and possible entry and exit points to buildings are under casual observation from neighbours or passers-by. In flats, restrict access to the rear of the building, and provide all footpaths with good lighting. Additional external lighting incorporating passive infrared detectors can be most useful. Appropriate planting can reinforce barriers, but make sure that vegetation does not affect visibility, or trees provide easy ways over barriers. 43-1
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Security
Table I Relationship between crime and building type Type of building
Principal risks
Vulnerable points
Design solutions
Single person/family dwellings
4, 5, 11
Ground-floor doors and windows
Doors and windows fitted with security locks that cannot be opened by merely breaking the glass Overlooking of all doors and windows from neighbouring properties, with adequate lighting from street lights etc
Upper windows near to low-level roofs, drainpipes, etc
Anti-climb paint or barbed wire on drainpipes Locks and visibility as above
Flats
3, 4, 5, 6, 11, 13
Door to flat, particularly where this opens off internal lobby, as no window is allowed by fire regulations. This means that criminals can often proceed without the possibility of being seen from a neighbouring flat
Solid door with bolts at hinge side in addition to security locks, bolts and spyhole Good lighting, proof against interference Minimum length of corridors, few corners
Multi occupancy dwellings
3, 4, 5, 6, 11, 13
Hostels
1, 4, 11
Generally as flats
Generally as flats
Communal areas
No architectural measures other than ensuring that fire exits cannot be used for unauthorised ingress
Rooms Hotels
1, 4, 5, 13
Kitchens, linen stores, rooms
Ensure that all exits are under constant casual observation at all times. This makes it difficult for staff or intruders to remove their booty A substantial safe should be provided near the reception for guests’ valuables. Safe less than 600 kg weight must be secured against bodily removal Master key system for rooms under good control
Shops
1, 2, 4, 5, 8, 9, 10, 11, 13
Ground-floor doors and windows
Security locks and easy observation
Back-up stores and rear corridors
Should be designed to be under constant casual observation. If not architecturally possible closed-circuit television can be used, although this may affect trade by alienating customers
Unfrequented areas of sales floor, fitting rooms in garment shops Offices
1, 4, 5, 8
Ground-floor doors and windows, particularly rear fire escapes
Panic-type locks on rear escape doors. All areas under constant casual observation Supply all staff with lockable furniture for personal valuables Consider a secure store for expensive items Computers to be fitted with anti-theft devices
Factories and storage buildings
1, 4, 5, 8, 9, 11, 13
Ground-floor doors and windows, lorry-loading banks
Doors barred with heavy-duty locks-in many cases machinery for cutting through such devices will be to hand Constant casual observation, including security patrolling at night Good fencing around the site, with permanent lighting of the area between fence and building
Sports buildings
1, 3, 5, 6, 8, 9, 10, 11, 13
Changing rooms, cash desk
Stout lockers, good observation, substantial safe for takings, if must be left on premises
Restaurants
1, 8, 9, 13
Kitchens, stores, cash desk
Constant casual observation
Banks
5, 7, 8, 9
Almost everything
Sophisticated security measures that are not generally known outside the particular organisation
Car parks
1, 2, 3, 4, 6, 8, 9, 10, 12, 13
1.07 References BS 8220: Guide for security of buildings against crime BS 8220-1 (2000): Dwellings BS 8220-2 (1995): Offices and shops BS 8220-3 (2004): Storage, industrial and distribution premises Oscar Newman, Defensible space, Architectural Press, 1972 Secured by design, new homes security scheme (Association of Chief Police Officers Project and Design Group, 1994)
Observation at all times, including the use of lighting and closed-circuit television. In this case public acceptance is universal
Secured by design, commercial (Association of Chief Police Officers Project and Design Group) Think Thief – A Designer’s Guide to Designing out crime (jointly produced by the Home Office and the Design Council) Ian Colquhuon, Design Out Crime: Creating Safe and Sustainable Communities, Architectural Press, 2003