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What does fire safety on a construction site involve?

Last checked 24-10-2026. A plain guide, not legal advice: check the official guidance below for your job.

CDM 2015 regulations 29 to 32 require you to take steps against fire, have emergency arrangements, keep escape routes clear, and provide fire detection and fire-fighting equipment where needed. HSE guidance HSG168 explains how to do it.

What the law requires

Regulations 29 to 32 of the Construction (Design and Management) Regulations 2015 sit in Part 4, which applies to construction sites (regulation 16).

  • Regulation 29: take suitable and sufficient steps to prevent, so far as is reasonably practicable, injury from fire or explosion.
  • Regulation 30: where necessary, make arrangements for any foreseeable emergency, including evacuation. People must be familiar with them and they must be tested by being put into effect at suitable intervals.
  • Regulation 31: where necessary, provide enough suitable emergency routes and exits. They must lead as directly as possible to an identified safe area, be kept clear, have emergency lighting where necessary, and be signed.
  • Regulation 32: where necessary, provide fire-fighting equipment and fire detection and alarm systems. They must be examined, tested and maintained, and the equipment must be easy to reach and signed. People must be instructed, so far as is reasonably practicable, in the equipment they may need to use, and nobody may do work with a particular fire risk unless suitably instructed.

HSG168 says HSE enforces fire precautions on construction sites, but where other people occupy the premises, regulation 36 gives the general fire precautions to the authority for occupied premises, usually the fire and rescue authority. HSG168 also lists other fire law that can apply, such as the Regulatory Reform (Fire Safety) Order 2005 and DSEAR 2002, so check which applies to your job.

HSG168 in outline

HSG168, Fire safety in construction (third edition, 2022), is HSE guidance on meeting those duties. HSE says following it is not compulsory, but doing so will normally be enough to comply. Part 1 is a five-step fire risk assessment: identify hazards, identify who might be harmed, evaluate and control the risk, record and inform, and review. Part 2 gives detail on ignition, fuel, escape, alarms and emergency plans. Part 3 covers the law.

HSG168 says the significant findings of the fire risk assessment should go into the construction phase plan.

Hot works

HSG168 recommends cold methods wherever possible, and a formal permit-to-work for hot work that cannot be avoided. CDM does not itself ask for a permit, but regulation 32 does require suitable instruction for work with a particular fire risk. Where DSEAR applies, check its own guidance too. HSG168 recommends:

  • A permit for a defined job and time, not a blanket permission, naming the location, the precautions, the person in control and the person who signs it off.
  • Loose combustibles cleared from the area, including the far side of a wall, and anything that cannot be moved protected with non-combustible board.
  • At least two suitable extinguishers within reach.
  • A fire watch during the work and at breaks, continuous for at least an hour afterwards, with another check two hours after. HSG168 says to finish hot work two hours before the end of the working day.

Flammables, LPG and waste

HSG168 recommends keeping flammable liquids and gases to a minimum, storing them outside in a secure place away from buildings and ignition sources, and keeping oxygen cylinders apart from LPG and acetylene. It calls LPG probably the largest single contributor to fire risk on construction sites, so appliances need proper standards, the correct regulator and competent installation, with Gas Safe engineers for fixed installations.

For waste, HSG168 recommends site rules so rubbish is cleared daily, skips kept outside and, if closer than 3 m to a structure, protected from spreading fire, and no burning of rubbish on site.

Alarms, escape and extinguishers

Beyond the regulations above, HSG168 recommends at least two escape routes in different directions, with nothing stored in them, and an assembly point where people are counted. It expects most sites to need an interconnected alarm that is audible in every work area, tested weekly. Extinguishers go at marked fire points, matched to the fire type, and are examined at least once a year. They are for small fires: HSG168 says not to delay calling the fire and rescue service.

Timber frame

HSG168 says an exposed timber frame can burn and spread fire rapidly, including to neighbouring properties, before the final fire protection is in. It recommends fitting cladding and fire stopping early, staggering deliveries to limit the fire load, putting the interconnected alarm in early, and carrying out an off-site risk assessment for neighbours.

Sources

Tools that help

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