In the UK, fire continues to be one of the most critical dangers on construction sites. Every year, a large number of fires in building or renovation projects are caused by predictable combinations, mainly highly flammable materials, sources of ignition, and sometimes overlooked modern hazards-particularly lithium-ion batteries.

The Joint Code of Practice sets critical standards to reduce risks and promote safety. The Regulatory Reform (Fire Safety) Order 2005 requires a “responsible person” to ensure fire risk is assessed and managed. For construction projects, duties under CDM Regulations 2015 also apply; all site fire-safety arrangements should be documented in the Construction Phase Plan.

Whether you’re a site manager, health & safety officer, principal contractor, or “responsible person”, understanding fire safety in construction is not just a legal obligation but a moral responsibility to protect lives and property.

Why are construction sites high risk for fire?

Fires on construction sites can be caused by various factors, often due to the dynamic and hazardous nature of the environment. Construction sites frequently feature temporary cabins such as offices, canteens, drying rooms, storage units, and welfare units. The Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation (JCoP), supported by insurers and fire-safety experts, states that:

• Temporary structures, particularly those situated within or near worksites (or within 10 metres of them), should ideally have fire-resistant walls, doors, and compartmentation, along with a fire-detection/alarm system that meets recognised standards.
• Following the recent update to BS 5839-1:2025 (Fire Detection & Alarm Systems for non-domestic premises), it is now strongly advised that most non-domestic buildings, including many temporary site units, are equipped with a formal fire-detection and alarm system, which includes manual call points, sounders, a control panel, or a wireless equivalent.
• Detection systems must be maintained throughout the construction phase, with temporary systems adjusted or relocated as the building progresses.

Implication for sites: If your site utilises cabins, canteens, drying rooms, storage units, or any temporary accommodations, you should regard them as buildings for fire-safety considerations. A wireless fire-alarm system (whether manual or automatic) is often warranted, especially considering the mobility and reconfiguration requirements during construction.

Key Principles to Fire Safety on Construction Sites

1. Fire risk assessment is essential: you need to identify fuel, ignition sources, and people at risk. Manage those risks before work commences.
2. Control combustible materials & waste: keep quantities at a minimum, store securely, and regularly dispose of waste.
3. Limit ignition sources & control hot work: welding, grinding, hot work must use a permit-to-work system; keep fire-fighting equipment ready.
4. Ensure safe means of escape, warning, and firefighting by maintaining clear escape routes, providing alarm or alert systems, and ensuring suitable extinguishers or fire points and safety stations.
5. Update the fire safety plan when site layout or processes change: for example, new buildings, material storage, the introduction of battery charging, or temporary accommodation.

Increased Fire Danger in 2026

Lithium-ion batteries in power tools, temporary lighting, and battery backup systems are now common on sites, but if not treated properly, they can present severe fire hazards. Thermal runaway from damaged or overheated cells can produce rapid, torch-like fires that are difficult to extinguish and may later flare up again.

Because of this, major insurers and fire safety bodies now consider lithium-ion battery fire as a key emerging threat, especially on building sites, storage facilities, or zones of battery charging or maintenance.

If your site either uses or has stored within it lithium-ion-powered equipment, especially charging onsite, then the fire risk assessment of your site needs to reflect the specific hazards presented by batteries; firefighting and storage procedures must be updated, and battery storage and charging managed with the same diligence as flammable liquids or gas cylinders.

Lithium-ion Battery Management Protocol

If your existing fire-safety policy does not explicitly mention lithium-ion batteries, add a “Battery Management” clause. Consider battery storage/changing/charging to be just as important as flammable liquid storage or gas cylinders. 

Common Fire Hazards on site

Flammable Materials

On a construction site, you’ll find various materials like wood and cardboard packaging that are very flammable and can increase the risk of fire. Additionally, paints, adhesives, fuels, and other flammable liquids can easily catch fire if they’re not stored or managed correctly. Foam and other insulation materials can also ignite rapidly, releasing harmful smoke. It is recommended that all flammable materials be stored in approved, well-ventilated and secure areas to avoid the risk of fire. All liquids and materials on a site should be clearly labelled in containers to avoid accidental misuse.

Hot Work Activities

Work on a construction site, such as welding, cutting, or grinding, can produce sparks that may ignite flammable materials nearby. Additionally, during soldering and brazing, the heat and flames generated can lead to a fire if proper precautions are not taken. It is recommended that safety stations, including fire extinguishers, be placed nearby.

Electrical Hazards

Construction sites frequently use temporary wiring, which can sometimes result in overloaded circuits or damaged cables, raising the risk of electrical fires. Additionally, the regular operation of portable electrical tools and machinery with exposed wires or overheating parts adds to the fire hazard. Overheated temporary lights can also ignite nearby flammable materials, and charging lithium-ion batteries overnight also poses a fire hazard.

Heating Equipment

Accidental fires can occur on construction sites due to the improper use of temporary space heaters. Additionally, storing gas cylinders or heating fuel incorrectly heightens the risk of explosions or fires.

Smoking

Smoking in unauthorised or unsafe areas on a construction site heightens the risk of fire. Discarded cigarette butts left in places with combustible materials can quickly spark a blaze. It is recommended that all sites have a designated smoking area far from flammable materials that are used by all workers.

Poor Waste Management

On a construction site, there are often lots of scrap or excess materials. Improperly disposing of flammable or reactive materials can result in dangerous fires. If wood offcuts, packaging materials, and dust piles are not regularly removed, they can easily ignite and contribute to a fire hazard.

Arson and Unauthorised Access

An unsecured site is more vulnerable to arson. Intruders may deliberately set fires or damage equipment so it’s essential for all sites to be properly secured.

Gas and Fuel Risks

Spills from equipment such as generators or vehicles can pose a fire risk on the premises. Additionally, gas leaks from cylinders utilised for cutting or heating may catch fire if they come into contact with sparks or flames.

Neglected Equipment

Failure to regularly inspect and maintain tools and equipment on site can result in issues that may trigger fires. When equipment is left running without supervision or is not functioning properly, it can overheat and catch nearby materials on fire.

Environmental Factors

Take extra precautions in extremely dry, hot or windy weather, as these conditions can lead to a quick spread of fire, particularly in open spaces.

What fire protection should be available on construction sites?

Fire protection measures on construction sites fall into two categories: active and passive systems. Both types play a crucial role in reducing risks and handling possible fire emergencies. Additionally, it’s vital to educate all workers about the fire hazards and safety protocols in place. A select group of workers should also receive specialised training to effectively extinguish small fires.

Active Fire Protection

• Fire Extinguishers: various types of extinguishers, such as foam, water, LFX or CO2, should be placed strategically across the site. Workers should also have training so they know how to use them effectively. This will help minimise the spread of any potential fires as trained workers will be able to act fast and put out any small fires before they grow out of control.
• Temporary Fire Alarms: wireless fire alarms and detection systems are critical on sites, especially in temporary and high-risk areas. All sites should install and maintain appropriate fire detection to alert workers and occupants to evacuate the area promptly and reduce the risk of injury or fatalities should a fire break out.
• Sprinkler Systems: temporary sprinkler systems can be installed in high-risk zones like storage areas for flammable materials such as lithium batteries. Although sprinklers are not mandatory, they do detect and suppress fires at an early stage, which will minimise damage and prevent the fire from spreading across a site.
• Fire Blankets: useful for controlling small fires and preventing the spread of flames, especially where hot works such as welding or grinding are taking place. Fire blankets are easy to use without training and are lightweight and portable.

Passive Fire Protection

• Fire-Resistant Materials: Opt for materials that are non-combustible or fire-resistant when constructing temporary structures.
• Fire Doors and Barriers: Fire doors and barriers are effective in keeping fires confined to designated areas.
• Site Layout: A well-planned layout, ensuring adequate space between flammable materials and potential ignition sources, enhances passive fire safety.

Guidelines for Ensuring Fire Safety on Construction Sites

Adhering to established guidelines is vital for reducing fire risks. The Joint Fire Code of Practice UK offers detailed instructions, so it’s important to consistently adhere to the best practices outlined below.

1. Fire Risk Assessment

• Conduct regular fire risk assessments to identify hazards such as flammable materials, ignition sources, and high-risk activities.
• Create and share a fire safety plan that outlines emergency procedures, escape routes, and important contact numbers. Additionally, include strategies for fire prevention.
• Update the fire safety plan whenever there are major changes to the layout or operations of the site. Sites should be organised to minimise fire risks, such as separating storage areas for flammable materials from ignition sources.

2. Site Housekeeping

• Maintain a clean site by regularly disposing of combustible waste.
• Store flammable liquids and gases in designated fire-safe zones, away from ignition sources.
• Segregate waste, scrap material, flammable liquids, packaging, and combustible materials and store in secure designated areas, preferably away from site accommodation or high-risk areas.

3. Hot Work Management

• Welding, cutting, and grinding (hot work) must be carefully managed with permits and supervision.
• Provide fire-resistant blankets and shields to protect surrounding areas.

4. Emergency Access and Exit

• Keep emergency exits and access routes clear and free from obstructions for fire services.
• Display emergency evacuation plans, contact details, and carry out regular drills to ensure preparedness.
• Signage should be used to highlight escape routes and designated assembly points in case of an emergency.

5. Fire Warning / Alarm Systems

• Manual call points with sounders may suffice for small sites.
• Medium/large/commercial-scale or multiple-unit sites: install a full fire-alarm system, wired or wireless, including manual call points, sounders, and a control panel, all linked to external monitoring if necessary, especially in the case of 24/7 site occupancy or complex site layout. In modern, dynamic sites, wireless systems may be more workable.
• Maintain/test the system routinely (weekly test of call points, regular inspection & servicing by competent personnel), keeping in line with JCoP and BS 5839. If you invest in a Polaris fire system, automatic silent tests are carried out by the system every minute. 

6. Firefighting Equipment & Fire Points

• Appropriate fire-fighting equipment according to the identified hazards – flammable liquids, combustible materials, Li-ion batteries, hot work, etc. Portable extinguishers shall be in conformance with the applicable British standard.
• Use conspicuous, easily accessible fire-point cabinets or trolleys with extinguishers, fire blankets, and other rapid-response equipment — especially near high-risk zones like chemical stores, charging rooms, and hot-work areas.
• Maintenance of extinguishers and safety-station equipment-including annual service, checks after use, and replenishment.

7. Lithium-ion Battery Storage & Charging Policy

• The new lithium-ion battery protocol includes inventory, designated charging rooms, fire-resistant storage, periodic inspection, and post-fire battery-handling procedures.

8. Training, Awareness and Documentation

• All workers are to receive fire-safety induction upon arrival: cover evacuation routes, alarm call-points, location of fire-points, battery protocol, hot-work procedures, waste management, use of fire extinguishers and emergency procedures.
• Assign fire marshals to oversee daily compliance and readiness for emergencies.
• Logbook/record keeping of: risk assessments, alarm-system tests, fire extinguisher servicing, hot-work permits, battery-storage/charging inventory, evacuations, and any fire incidents. These provide compliance, insurance, and continuous improvement.

 What to Do If a Fire Breaks Out on a Construction Site?

Despite preventive measures, fires can still occur. Knowing how to respond can make a critical difference:

1. Raise the Alarm

• Activate the nearest fire alarm.
• Immediately contact emergency services, giving them clear information about where the fire is and what type it is.

2. Evacuate the Site

• Follow the site’s evacuation plan, making sure all workers move to the designated assembly points and are accounted for.
• Do not attempt to retrieve personal belongings or tools during evacuation.

3. Fight Small Fires (If Safe)

• If you have had adequate training and it is safe to do so, use the appropriate fire extinguisher to tackle a small fire.
• If the fire is too large, raise the alarm and leave the area quickly. Always prioritise your safety.

4. Assist Firefighters

• Give the fire service up-to-date site plans and information about any hazardous materials present.
• Ensure that firefighters can access the site without any obstacles.

Fire prevention on construction sites is a shared responsibility that demands constant attention, compliance with regulations such as the Joint Fire Code of Practice UK, and commitment to best practices. By ensuring proper fire safety measures, providing comprehensive training, and promoting a culture of awareness, the likelihood of fire incidents can be significantly reduced.

Remember, the cost of negligence is far greater than the effort required to maintain a fire-safe construction site. Invest in fire protection measures, enforce strict safety protocols, and ensure everyone on site knows their role in preventing and responding to fires. Safety isn’t just about compliance – it’s about saving lives.