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Construction compliance guide

Fire Safety on Construction Sites: Prevention and Planning

Construction sites are high-risk environments for fire. Here is what the law requires, how to manage hot works safely, and how to plan evacuation on a building that is still going up.

Why fire risk is higher on construction sites

Construction sites present a combination of fire risks that you simply do not find in finished buildings. Understanding why sites are so vulnerable is the first step towards managing the risk properly.

  • Incomplete fire barriers. In a finished building, fire doors, compartment walls, and fire-stopping materials slow the spread of fire and buy time for evacuation. On a construction site, none of these are in place yet. Fire can spread unchecked through an entire structure in minutes.
  • Exposed timber frames. Timber-frame buildings are particularly vulnerable during construction. Before cladding, plasterboard, and fire barriers are installed, the structural timber is fully exposed and highly combustible. Several major fires in the UK have destroyed timber-frame buildings during the construction phase.
  • Flammable materials stored on site. Solvents, adhesives, paints, LPG cylinders, foam insulation, timber, packaging — construction sites are full of combustible and flammable materials, often stored in large quantities and sometimes closer together than they should be.
  • Hot works. Welding, cutting, grinding, and the use of blowtorches are common on construction sites and are one of the leading causes of construction site fires. A single spark landing on sawdust, packaging, or insulation material can start a fire that destroys the entire project.
  • Temporary electrical supplies. Construction sites rely on temporary electrical installations that are more prone to faults, overloading, and damage than permanent wiring. Cables get run over by plant, connections get wet, and distribution boards get knocked about. All of these increase the risk of electrical fires.
  • Arson on unoccupied sites. Construction sites are often unoccupied at night and over weekends, making them targets for arson and vandalism. Sites with poor perimeter security, easily accessible materials, and no CCTV are particularly vulnerable. Arson is consistently one of the top causes of construction site fires in the UK.

The legal framework

Fire safety on construction sites is governed by two key pieces of legislation and one industry standard that most insurers and clients expect you to follow:

Regulatory Reform (Fire Safety) Order 2005

The Fire Safety Order applies to all workplaces in England and Wales, including construction sites. It requires the responsible person to carry out a fire risk assessment, implement appropriate fire safety measures, and keep the assessment under review. On a construction site, the responsible person is usually the principal contractor or the person in control of the site. The Order is enforced by the local fire and rescue authority, and failure to comply is a criminal offence.

Health and Safety at Work etc. Act 1974

The general duty to ensure the health, safety, and welfare of employees and others affected by your work includes fire safety. The HSE can take enforcement action where fire risks on a construction site are not adequately managed, particularly where they relate to the storage of flammable materials, use of temporary electrical installations, or lack of emergency procedures.

Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation

Published by the Fire Protection Association and endorsed by the construction industry and insurers, the Joint Code of Practice (JCoP) is the recognised industry standard for construction site fire safety. It is not law, but it represents good practice and most insurance policies require compliance. It covers fire risk assessment, hot works, temporary accommodation, storage of materials, security, and emergency planning. If you follow the JCoP, you are very likely to satisfy the legal requirements as well.

Fire risk assessment on site

A fire risk assessment on a construction site follows the same basic principles as any fire risk assessment, but the constantly changing environment makes it more demanding. Here is what you need to do:

1.Identify sources of ignition

Walk the site and note everything that could start a fire: hot works, temporary electrical supplies, heaters, smoking areas, plant and vehicles, and the possibility of arson. Do not forget less obvious sources like halogen work lights, battery chargers, and friction from cutting or drilling.

2.Identify sources of fuel

List all combustible and flammable materials on site: timber, insulation, packaging, solvents, adhesives, LPG cylinders, diesel, waste materials, and anything else that could burn. Pay attention to how materials are stored and whether they are separated from ignition sources.

3.Evaluate who is at risk

Consider everyone on site — your own workers, subcontractors, visitors, delivery drivers, and members of the public near the site boundary. Think about people who may be working in confined or elevated positions where escape would be difficult.

4.Record findings and implement controls

Write down the significant findings, the measures you are putting in place, and who is responsible for each one. Controls might include segregating flammable materials, implementing hot works permits, improving site security, establishing fire points, and creating a clear evacuation plan. Review the assessment regularly — and always when site conditions change.

Hot works permits

Hot works are one of the leading causes of fire on construction sites. A robust permit system is essential. Here is what you need to know:

What counts as hot works

Any operation that produces sparks, naked flames, or significant heat. This includes welding, flame cutting, oxy-acetylene work, grinding, soldering, brazing, use of blowtorches, bitumen boilers, and any tool or process that could ignite combustible materials nearby.

The permit system: before

Before hot works begin, the area must be inspected and cleared of combustible materials for a minimum radius of 10 metres (or further if conditions require it). Combustible materials that cannot be moved must be covered with fire-resistant sheeting. A suitable fire extinguisher must be positioned within immediate reach. The permit must be completed and signed by the person authorising the work.

The permit system: during

While hot works are in progress, the operative must remain vigilant for signs of fire. A dedicated fire extinguisher must be immediately available. If conditions change — for example, if combustible materials are moved into the area or the wind picks up — work must stop until the situation is reassessed.

The permit system: after (fire watch)

After hot works cease, a fire watch must be maintained for a minimum of 60 minutes. This means someone physically staying in the area and checking for signs of smouldering, smoke, or fire. Many site fires start after hot works have finished, when operatives have left and a smouldering ember ignites nearby material. Some insurers require a fire watch period of up to four hours.

Designated hot works area

Where possible, set up a designated hot works area — a cleared, fire-resistant zone where welding, cutting, and grinding can be carried out with reduced risk. This is not always practical on a construction site, but where it can be done, it significantly reduces the likelihood of fire.

Fire points and equipment

Fire points are designated locations on site where firefighting equipment is readily accessible. They are a core requirement of the Joint Code of Practice and a practical necessity on any construction site.

  • Extinguisher types. Water extinguishers for general combustibles (Class A), dry powder for flammable liquids and gases (Class B/C), and CO2 for electrical fires. On most construction sites, a mix of water and dry powder provides reasonable coverage. Position CO2 extinguishers near temporary electrical installations and site offices.
  • Positioning. The Joint Code of Practice recommends that fire points should be positioned so that no one on site has to travel more than 30 metres to reach one. Mark each fire point clearly with signage visible from a distance. Keep fire points free of obstruction at all times — do not stack materials in front of them.
  • Signage. Use standard fire safety signage to mark fire points, escape routes, and assembly points. Signage must be visible even in poor light or dusty conditions. Replace damaged signs immediately.
  • Access routes. Maintain clear access routes for the fire service at all times. This includes keeping the site entrance clear for fire appliances, ensuring hard-standing areas can support the weight of a fire engine, and making sure hydrants or water supplies are accessible and clearly marked.

Evacuation planning on partially built structures

Evacuating a building that is still under construction is very different from evacuating a finished one. The permanent escape routes shown on the architect’s drawings do not exist yet, and the layout changes with every phase of the build.

Challenges

No permanent escape routes, constantly changing floor layouts, multiple levels without finished stairwells, scaffolding as the only means of descent, multiple contractors working in different areas, high noise levels that can mask alarms, and restricted access points caused by plant, materials, and temporary works.

Temporary escape routes

Identify and mark temporary escape routes at each stage of the build. These must be kept clear of materials, waste, and obstructions. On multi-storey structures, consider temporary stairwells, scaffold access towers, or other means of vertical escape. Review routes every time the site layout changes.

Assembly points and roll call

Establish assembly points at a safe distance from the building and any material storage areas. Use your site induction register to carry out a roll call after every evacuation. Everyone on site — including visitors and delivery drivers — must be accounted for. Appoint fire marshals for each zone or floor on larger sites.

Alarm systems

A standard fire alarm bell may not be heard on a noisy construction site. Consider air horns, battery-powered portable sounder units, or a combination of audible and visual alarms. Make sure every person on site knows what the alarm sounds like and where to go when they hear it. Test the alarm regularly.

How The Site Book includes fire safety

Fire safety should not be an afterthought — it needs to be built into your project documentation from the start. The Site Book handles this automatically.

When you describe your project, The Site Book identifies fire risks and flags them in your RAMS. If your project involves hot works — welding, cutting, grinding — the RAMS will include hot works precautions, permit requirements, and fire watch procedures. If you mention timber framing, LPG storage, or temporary electrics, the relevant fire safety controls are included.

Your Construction Phase Plan includes a fire safety section covering emergency procedures, fire point locations, and evacuation arrangements. This is exactly what an HSE inspector or fire and rescue officer will want to see if they visit the site.

The result is a set of documents that already accounts for fire safety — with the right controls, procedures, and emergency plans built in. You review it, adjust anything that needs changing, and download professional documentation that covers your fire safety obligations as part of your wider compliance paperwork.

Frequently asked questions

Common questions builders ask about fire safety on construction sites.

Do I need a fire risk assessment for a construction site?

Yes. The Regulatory Reform (Fire Safety) Order 2005 applies to construction sites just as it applies to any other workplace. The responsible person — usually the principal contractor or, on smaller jobs, whoever is in control of the site — must carry out a fire risk assessment before work begins and keep it under review as the project progresses. The assessment must identify sources of ignition and fuel, evaluate who might be at risk, and record what measures are in place to prevent fire and protect people if one breaks out. On a construction site, the risk profile changes constantly as new materials arrive, structures go up, and different trades come and go. That means your fire risk assessment is not a one-off document — it needs updating whenever conditions change significantly. The HSE and local fire and rescue authorities can both ask to see your fire risk assessment, and failing to have one is a criminal offence under the Fire Safety Order. For most construction projects, the fire risk assessment should be referenced in the Construction Phase Plan and reflected in your site-specific RAMS.

What is a hot works permit and when do I need one?

A hot works permit is a formal, written authorisation to carry out any work that produces sparks, flames, or significant heat in an area where there is a risk of fire. Hot works include welding, flame cutting, grinding, soldering, use of blowtorches, and any operation involving open flames or equipment that generates enough heat to ignite nearby materials. You need a hot works permit whenever these activities take place outside a designated hot works area — and on most construction sites, that means virtually every time. The permit system works in three stages: before, during, and after the work. Before the work starts, the area must be inspected to identify and remove or protect combustible materials within a specified radius (typically at least 10 metres). During the work, a fire extinguisher must be immediately available and the operative must remain alert to any signs of fire. After the work finishes, a fire watch must be maintained for a minimum of 60 minutes — many insurers and the Joint Code of Practice recommend this as an absolute minimum. The permit should name the person carrying out the work, the location, the duration, and the specific precautions taken. Hot works permits are a standard requirement of construction site fire safety and are often a condition of site insurance policies.

What fire extinguishers do I need on a construction site?

The types and number of extinguishers you need depend on the fire risks present on your site, but as a general rule you should have water extinguishers for general combustible materials (wood, paper, textiles), CO2 extinguishers for electrical fires, and dry powder extinguishers for flammable liquid and gas fires. On most construction sites, a combination of water and dry powder extinguishers provides reasonable coverage. If you have a site office with electrical equipment, a CO2 extinguisher should be located there. For hot works, a fire extinguisher rated for the materials in the immediate area must be within arm’s reach of the operative at all times. The Joint Code of Practice recommends that fire points — designated locations with extinguishers, signage, and sometimes a fire alarm call point — should be positioned so that no one on site has to travel more than 30 metres to reach one. Extinguishers must be inspected regularly, kept in accessible locations (not buried behind materials or scaffolding), and everyone on site should know where they are. Annual servicing by a competent person is a legal requirement. Consider the specific risks on your site: if you are storing LPG cylinders, solvents, or large quantities of timber, you may need additional or specialist extinguishers beyond the standard provision.

Who is responsible for fire safety on a construction site?

Under the Regulatory Reform (Fire Safety) Order 2005, the “responsible person” holds the primary duty for fire safety. On a construction site, this is typically the employer or the person who has control of the premises — in practice, the principal contractor on notifiable projects, or the contractor in control of the site on smaller jobs. However, fire safety responsibility is not limited to one person. Under CDM 2015, the principal designer must consider fire safety as part of the design process, and every contractor on site has a duty to cooperate and coordinate on fire safety matters. If you are a subcontractor, you are responsible for managing fire risks arising from your own work — including hot works, storage of flammable materials, and ensuring your workers know the evacuation procedures. The client also has duties: they must make sure that adequate arrangements are in place for managing fire safety throughout the project. On domestic projects where there is no principal contractor, the contractor doing the work takes on the fire safety responsibilities. The key point is that fire safety is a shared responsibility. Everyone on site has a role, from the client who sets the expectations down to the individual operative who must follow the rules, report hazards, and know the escape routes.

How do I plan evacuation on a site that is still being built?

Evacuation planning on a partially built structure is one of the most challenging aspects of construction site fire safety, because the layout, access routes, and structural conditions change constantly. Start by identifying the escape routes available at each stage of the build. These will not be the permanent escape routes shown on the architect’s drawings — they are temporary routes that reflect the current state of the structure. Mark them clearly with signage and keep them free of obstructions, materials, and debris at all times. Consider how people will be alerted to a fire. On a noisy construction site, a standard fire alarm may not be heard. You may need air horns, portable sounder units, or a combination of audible and visual alarms. Make sure everyone on site knows what the alarm sounds like and what to do when they hear it. Establish assembly points away from the building and any material storage areas. Carry out roll calls using your site induction register so you can confirm that everyone is accounted for. On larger sites with multiple contractors, appoint fire marshals for each zone or floor and make sure they know their responsibilities. Review and update your evacuation plan every time the site layout changes significantly — when a new floor is added, when scaffolding is erected or struck, when access routes change. Practise fire drills regularly. On longer projects, the Joint Code of Practice recommends drills at least monthly. Brief every new person on the evacuation plan as part of their site induction.

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