Use a blowtorch next to a stack of polystyrene insulation blocks, polythene-wrapped to a wooden pallet, and sooner than you can cite the health and safety code, you've got a roomful of poison gas. Something like this happens 11 times a day on UK sites. Tom Lane asks what's going wrong
On Wednesday 14 november, A thick plume of smoke rose into the air over Bow in east London. Traffic seized up as the smoke spread, and fire engines had to inch their way through clogged roads. When they arrived, 20 builders and the residents of the block of flats they were working on had to be evacuated, then 30 firefighters battled for several hours to bring the blaze under control. By the time they left, half the roof and floor were destroyed. The fire brigade believes that the fire started in the roof where the builders were working, and are investigating its cause.

In this case, nobody was hurt, but 11 fires occur on construction sites every day. Between 1996 and 2000, 179 construction workers were injured in them. Even if there are no human casualties, the building programme will be dead on arrival — and if it is discovered that the contractor was not following the Fire Protection Association's code of practice, introduced after the £120m Minster Court fire in 1990, the insurance company may not pay out.

Several documents exist that seek to protect property and people from fire on sites, but experts agree that they are inadequate. Peter Bressington, director of consultant Arup Fire, says: "The Health and Safety Executive does give guidance on escape, but in a very prescriptive fashion. It doesn't give any guidance on how to achieve this and what you should do."

Shortcomings in the guidance are easy enough to find, and make construction sites a constant fire hazard. Part B of the Building Regulations, which deals with fire safety, is only concerned with the users of a completed building. So, for example, polystyrene can be used as an insulation material providing it is made fire safe in the finished building, but an inspector walking past a pile of it on site has no authority to do anything about the risk it presents.

More generally, a lot of rubbish is generated on sites as materials arrive wrapped in polythene on wooden pallets. People then work on top of them with angle-grinders, blowtorches and welding equipment.

If a fire does start on site, workers may find that protection and escape measures offer little chance of escape and no protection. The stairs may be blocked by equipment, for example, and fire doors will probably not have been fitted because the contractor does not want them damaged. The sprinkler system may well not have been commissioned, or someone is working on it and turned off the water supply without telling anyone. And so on …

Bressington says the HSE regulations are too inflexible to adapt to a dynamic work situation. The regulations contain tables that identify how far from a place of safety site workers should be. These distances vary according to the level of risk and whether the building is enclosed or semi-open. "The guidance doesn't go far enough or set performance guidelines," says Bressington. "For example, it doesn't define what an open building is, it doesn't define what is low, medium or high risk and there are no options on escape routes."

He adds: "The HSE should give practical guidance on how to get the safety distance. There is no guidance or alternatives given; it's just 50 m and that's it."

The answer could be clearer and more practical guidance from the HSE, particularly on risk analysis, says Bressington. Armed with this, contractors could focus resources on the high-risk phases of a project. Bressington believes that smaller contractors need more help: "For smaller sites, they need a straightforward methodology that takes them through the process and explains what the problems are.

They then need to implement the Construction (Design and Management) Regulations, and address escape and compartmentalisation issues."

The HSE has responded to this criticism with an offer to help the industry come up with improved guidance. It said: "The HSE would welcome an industry initiative to produce guidance on fire safety during construction, and we would be happy to support them in the production of such guidance."

Jeremy Hodge, managing director of the fire and risk sciences division of BRE, agrees.

"The problem with the regulations is that they are a bit red-tapey for a small company; it must be easy for these people to do." But he is unwilling to let contractors off the hook entirely: poor site practice is also a problem.

"The larger the main contractor, the more likely it is to work well," he says. "The small sites are the problem as the smaller contractors are unaware of fire-prevention issues."

Another player in the fire safety game is the client. Some organisations have recognised that having your tower burn down halfway through construction was bad business practice, and have seized the initiative on fire safety. Canary Wharf engaged Arup Fire to advise on its fire-prevention strategy, as a result of which it put in place a fire-safety plan that is continually reviewed as work progresses, and that is communicated to all staff. It installed fire-suppression systems as early as possible in the project and now has a team of people constantly clearing rubbish. Close co-ordination of these teams ensures that everyone has two escape routes with fitted fire doors. Staff have to attend regular fire-safety seminars, and there is a no-smoking rule on site, except in designated areas.

The National Trust is possibly the most pyrophobic client in the UK – partly the result of the disastrous fire at Uppark House, Hampshire, in 1989, which resulted in £22m of damage.

It was caused by a contractor working on its lead roof and the trust successfully pursued it through the courts. The upshot is a construction process tailored to avoid fires: it makes extensive use of prefabrication and a special dispensation is necessary to before hot work is carried out – and a trust staff member supervises it while it happens and for two hours after it finishes.

Fire safety strategies

  • Devise and implement a safety plan
  • Hold fire safety seminars
  • Effective communication will keep staff aware of any fire safety changes
  • Focus fire prevention resources on high-risk phases of project
  • Improve security measures to prevent the risk of arson
  • Implement a hot-work permit system
  • Try and get suppliers to use less protective packaging
  • Clear rubbish from site regularly
  • Store materials safely away from fire hazards
  • No smoking except in designated areas
  • Ban bonfires
  • Check fire extinguishers regularly
  • Many site fires start in temporary accommodation: exercise particular vigilance here
  • External lifts can be a good way of escape from tall buildings, so include in any fire safety plan
  • Have at least two escape routes out of building
  • Connect sprinkler and fire-ventilation systems early on in the project
  • Install fire doors as soon as possible
  • Make sure all subcontractors have insurance cover for value of project

What rules do contractors have to follow?

There are two regulations published by the Health and Safety Executive that are concerned with fire on construction sites. The Construction (Design and Management) Regulations 1994 are concerned with design and planning to increase site safety. The Construction (Health, Safety and Welfare) Regulations 1996 are intended to prevent fires starting and protect people if one does breaks out. There is also a code of practice called Fire Prevention on Construction Sites, which is intended to protect property from being damaged. In the late 1980s and early 1990s, there was a spate of major fires on sites – including the 1990 fire at Minster Court in the City, which cost £120m. Rather than bumping up premiums, the insurance industry responded with this code of practice, first published in 1992 by the Fire Protection Association and the Construction Confederation. Contractors are meant to abide by its guidance if they want cover on their projects to be valid. Jeremy Hodge of BRE says the number of fires has dropped since its introduction.