Roofs and buildings - preventing and controlling unauthorised access

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History has shown that unauthorised access to premises and climbing onto roofs can seem an attractive and exciting activity to children. These children are not always intent on causing mischief either, as all too frequently fatal accidents occur when young boys venture onto roofs (often school premises) to retrieve footballs that have been inadvertently kicked onto the buildings. On sites with inadequate security arrangements you may also find roofs can provide an effective route for thieves to enter. But did you realise that if such an uninvited visitor were to fall or be otherwise injured those persons in control of the premises may be found liable?

Single storey buildings with flat or gently sloping roofs are most prone to unauthorised access because of the relative ease with which people can climb onto them, particularly when equipment or materials is left around that facilitate their access. A wheelie bin or disused drum etc. can make an impromptu step when pushed up against the wall of a building.

Roofs of buildings are often not designed to withstand the weight of people walking across them and are seldom provided with barriers at the edge to prevent falls. Some roofing materials and features such as skylights may be particularly fragile (or become fragile with age) so pose one of the greatest risks of people falling through.

As part of their risk management strategy, employers and building managers may consider introducing control measures to protect the premises and occupants from intruders. However, some of these deterrents - high fences, barbed wire or anti-climb paint for example – are also potential causes of injury to unwanted guests. So how far can you justify using them, and what does the law deem acceptable?

Legal Position

Under the Occupiers' Liability Act 1957, occupiers (persons in control of the premises) have a duty to take reasonable care to ensure the safety of visitors using their premises for the purpose they were invited. The Occupiers' Liability Act 1984 extended this duty to impose some responsibility on occupiers to protect uninvited visitors, including trespassers.

The duty of care under the 1984 Act takes effect if:

  • you know (or have reasonable grounds to believe) there is a danger
  • you know (or have reason to believe) that people may be in, or come into, the vicinity of the danger
  • the risk is one against which you may reasonably be expected to offer some protection

Where these criteria apply, occupiers have a duty to take reasonable care that people don't suffer injury. It may be possible to discharge this duty of care by warning people about a danger, or by discouraging them from coming into contact with it.

Section 4 of the Health and Safety at Work Act also requires those in control of workplaces to take reasonably practicable measures to ensure their premises are safe for the benefit of non-employees. This extends to means of access and egress, and any plant and substances at the site.

Risk Assessment

To decide what are proportionate measures in your particular circumstances will require a risk assessment to be carried out.  It is essential that a competent person evaluates and documents the health, safety and security risk for all your premises, including any derelict or disused sites.

The risk assessment should begin with identifying the hazardous elements of the premises and should consider any historic deterrents that may already exist such as glass embedded into the tops of walls etc. that are unlikely to be regarded as acceptable nowadays. Where natural features exist on site that could be dangerous e.g. ponds or lakes these may not require the same level of control exercising over them as a manmade hazard that you have allowed or created, but it should be recognised that such features could lure some people in.

Your assessment should consider not only the site's layout and condition but also its location in relation to local populations, points of access and who might stray onto it. For example, if it is known that children from nearby estates gain access to play on the grounds at weekends or during school holidays.

Control Options

Having now established what the hazards and risks are, you will need to determine whether additional control measures are needed and if so what things can be done. The range of options is huge but you should seek solutions that are both effective at combating the risk and practical to implement and maintain.

Straightforward measures should be established that include site closure procedures to ensure all doors, windows and perimeter gates are locked shut, along with the removal of items like ladders or other equipment that could be used to gain access or force entry to premises. As malicious and illegal practices are most likely to take place in the hours of darkness, illuminating the premises and providing CCTV may help curb unwanted activity. However, security lighting and cameras will need protecting from attack and may require shatterproof lenses or guards installing.

Drainpipes or other similar services running up walls may provide a viable structure for an agile climber. Where these features exist it may be possible to enclose them behind a shroud that prevents a good grip being obtained or if this is not feasible spiked collars might be attached to inhibit progress.

The level of security will be determined by the nature of the site and the risks envisaged, but to some extent you will also have to consider the security arrangements of neighbouring premises as an intruder is likely to attempt entry to the easiest target.

The determined intruder is unlikely to be stopped by an electronic alarm but physical deterrents such as shutters on doors and windows can create a significant obstacle, although they are often unsightly.

When it comes to introducing new deterrents, the primary objective should be to keep people out, rather than creating traps.

Where there are walls, fences or trees etc. in close proximity to buildings consider whether these create means of access to roofs. If so, the solution may be as simple as having the overhanging branches removed or applying anti-climb paint (a non-setting gel or oily substance that makes the surface it coats slippery) to the edges of a low roof or wall. However, where anti-climb paint is used you need to make sure it is applied where it will avoid accidental contact with legitimate visitors to the site. It certainly should not be used in areas where access might be needed from time to time e.g. for property maintenance.

Similarly, if barbed or razor wire is used (not that the latter is a proportionate measure in most situations) it should be installed well above head height - usually above 2.4 metres from the ground.

By introducing hazardous elements you will of course need to highlight their presence by displaying prominent signage, at regular intervals on the approach to them. The same is true if fragile surfaces exist on roofs.

With buildings that are remote, unoccupied or rarely used you may wish to consider removing all assets of any value (including valuable building materials such as copper and lead etc.) displaying notices to that effect on the exterior. If such premises begin to suffer from vandalism or graffiti, there should be procedures in place to clean and repair them;  a property that is left in a visibly poor condition is likely to become increasingly targeted.

Depending upon the level of risk anticipated another option to deter intruders from accessing premises can be to provide a physical security presence, either as a shared resource with neighbouring properties or as an extension to day time arrangements. Even if this level of control cannot be justified it is still worthwhile fostering a good relationship with the local police to seek assistance with monitoring what’s happening on site and alerting them to any significant incidents or unwanted activity.

Ongoing Regime

Protecting your premises is not a one off exercise so it is essential to have a plan to regularly review all elements of your access arrangements. This plan should start with a periodic review of the risk assessment taking into account the following:

  • How has the use of the buildings changed?
  • Have the premises deteriorated?
  • Are routine inspections highlighting any deficiencies in the control measures?
  • Are repair and maintenance activities being fulfilled?
  • Have there been any changes to staff or contractors with site security responsibilities and if so have they received sufficient information and training to fulfil their duties.
  • Have local demographics and crime rates changed?
  • Have there been any reports of security breaches and have the causes been investigated?

Once you have reviewed the risk assessment you are likely to have discovered some improvement opportunities. These should then feature as part of your ongoing risk management action plan for the next period.

Finally, to reiterate the key message here is that to avoid liability you need to be able to demonstrate you have considered the foreseeable risks associated with visitors to your premises (invited or otherwise) and that you acted reasonably to control those risks in your particular circumstances.

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