The Most Common Fire Hazards in UK Office Buildings

Introduction

Office fires are rarer than they used to be, but when they happen the impact can be severe: injuries, business interruption, data loss, reputational damage, and regulatory scrutiny. The good news is that most office fires are preventable.

In the UK, fire safety is governed primarily by the Regulatory Reform (Fire Safety) Order 2005 (and equivalent legislation in Scotland and Northern Ireland). In plain English: a “responsible person” must assess fire risk, put proportionate controls in place, maintain them, and train staff.

This guide breaks down the most common fire hazards found in UK office buildings, why they’re risky, and what good control looks like in practice.

1) Electrical faults and overloaded circuits

Electrical issues remain one of the leading causes of fires in commercial premises. In offices, the risk often comes from everyday habits rather than dramatic failures.

Typical office causes

• Overloaded extension leads and multi-plug adapters (“daisy chaining”)

• Damaged cables (crushed under chair wheels, trapped under desks)

• Loose plugs, hot transformers, and worn sockets

• Portable heaters plugged into extension leads

• Poorly maintained fixed wiring

Why it’s dangerous

Overloading causes heat build-up. Heat plus insulation breakdown can lead to arcing, ignition, and rapid fire spread—especially where cables run through voids or under raised floors.

Practical controls

• Ban daisy chaining and set clear rules for extension lead use

• Use fused extension leads with surge protection where appropriate

• Arrange periodic fixed wiring inspections (EICR) by a competent electrician

• Implement Portable Appliance Testing (PAT) based on risk, not habit

• Replace damaged leads immediately; don’t “tape and hope”

• Keep electrical intakes, risers, and server rooms tidy and ventilated

2) Portable heaters and heat-producing appliances

Portable heaters are a common “quick fix” in draughty offices, but they can be a major ignition source.

Typical office causes

• Fan heaters placed under desks near paper bins

• Heaters too close to curtains, upholstered chairs, or coats

• Heaters left on overnight

• Kitchen appliances (toasters, microwaves) used incorrectly or left unattended

Practical controls

• Prefer building-level heating fixes over personal heaters

• If heaters are allowed, specify approved types (tip-over cut-out, thermostatic control)

• Enforce clearance zones around heaters (e.g., 1 metre where feasible)

• Switch-off checks at end of day (security or floor wardens)

• Keep kitchen appliances clean and maintained

3) Poor housekeeping and combustible storage

Offices contain plenty of fuel: paper, packaging, furniture, and waste. Poor housekeeping turns small incidents into big ones.

Typical office causes

• Paper stored against electrical equipment or heaters

• Waste bins overflowing, especially with shredded paper

• Cardboard and packaging stored in corridors or plant rooms

• Stockpiles of archived files in cupboards without ventilation

Practical controls

• Keep escape routes and stairwells clear at all times

• Use metal bins for high-volume paper waste where appropriate

• Remove waste daily; increase frequency during busy periods

• Store archives in designated areas away from ignition sources

• Keep plant rooms and electrical cupboards free of storage

4) Kitchens, break areas, and “small cooking” risks

Even where there’s no full canteen, small kitchenettes can be a hotspot.

Typical office causes

• Toasters and grills with crumb build-up

• Microwaves used with unsuitable containers

• Portable cooking devices brought in by staff

• Tea towels, paper towels, and packaging near hot surfaces

Practical controls

• Set rules: approved appliances only, no personal hot plates

• Clean toasters and microwaves routinely (assign ownership)

• Keep combustibles away from heat sources

• Provide suitable fire blankets/extinguishers where risk justifies it

• Ensure extraction/ventilation is adequate in larger kitchens

5) Smoking, vaping, and improper disposal

While indoor smoking is banned, smoking areas and entrances can still create risk.

Typical office causes

• Cigarette ends disposed into general waste

• Smoking near combustible external cladding, bins, or stored pallets

• Staff vaping in hidden corners or toilets

Practical controls

• Provide a designated smoking area away from doors, bins, and combustibles

• Use safe, fire-resistant cigarette bins and empty them safely

• Enforce no-smoking/no-vaping policy inside the building

• Keep external waste storage secure and away from the building line

6) IT equipment, server rooms, and battery risks

Modern offices run on IT. Concentrated equipment and batteries can increase fire load and introduce specific ignition risks.

Typical office causes

• Overheating laptops, docking stations, and chargers

• Poor ventilation around printers and photocopiers

• Server rooms with blocked airflow or dust build-up

• Lithium-ion batteries (laptops, power banks, e-bikes/scooters) charging unsafely

Practical controls

• Keep vents clear; don’t store paper against equipment

• Maintain printers/copiers and keep them away from combustible storage

• Use dedicated, ventilated comms/server rooms with access control

• Implement a safe battery charging policy (approved chargers, no overnight charging where possible)

• Consider fire detection appropriate to server rooms and critical areas

7) Hot works and contractor activities

Many serious fires start during maintenance: roofing, welding, cutting, soldering, or even using blowtorches for plumbing.

Typical office causes

• Contractors working without a permit-to-work

• No fire watch after hot works

• Combustibles left nearby (dust, insulation, packaging)

Practical controls

• Use a hot works permit system with clear sign-off

• Require contractors to provide RAMS (risk assessments and method statements)

• Clear combustibles and protect surfaces before work starts

• Maintain a fire watch during and after hot works (often 60 minutes or more, depending on risk)

• Verify contractor competence and insurance

8) Blocked fire doors, wedged doors, and compromised compartmentation

Fire doors and compartmentation are designed to slow fire and smoke spread. They only work if they’re not interfered with.

Typical office causes

• Fire doors wedged open for convenience

• Damaged door closers or missing intumescent strips

• Cable penetrations through walls/ceilings not fire-stopped

• Propped open riser cupboard doors

Practical controls

• Educate staff: wedging fire doors can put lives at risk

• Use compliant hold-open devices linked to the fire alarm where needed

• Inspect fire doors routinely (including seals, closers, latches)

• Ensure any building works include proper fire stopping

• Keep risers and service cupboards locked and tidy

9) Inadequate fire detection, alarm maintenance, and emergency lighting

Even with good prevention, early detection and safe evacuation are essential.

Typical office causes

• Disabled detectors due to false alarms

• Poor detector placement after office reconfigurations

• Fire alarm not tested or maintained

• Emergency lights not tested or batteries failing

Practical controls

• Maintain fire alarm systems to relevant British Standards

• Test alarms routinely and log results

• Review detector coverage after layout changes

• Maintain emergency lighting and conduct periodic full-duration tests

• Train staff on alarm response and evacuation procedures

10) Storage of flammables and cleaning chemicals

Most offices have small amounts of flammable liquids: aerosols, solvents, cleaning products, and sometimes printing supplies.

Typical office causes

• Aerosols stored near heat sources

• Cleaning chemicals stored in random cupboards

• Large quantities of alcohol-based hand sanitiser stored improperly

Practical controls

• Store chemicals in appropriate cupboards, away from ignition sources

• Keep quantities to a sensible minimum

• Follow COSHH assessments and supplier guidance

• Ensure lids are secure and containers are in good condition

11) External fire risks: bins, loading areas, and arson

External fires can spread into buildings through doors, windows, or cladding, especially if waste is stored against the building.

Typical office causes

• Wheelie bins stored under canopies or next to exits

• Pallets and packaging stored near the building

• Poor lighting and unsecured rear entrances

Practical controls

• Store bins and combustibles away from the building (and secure them)

• Improve lighting and CCTV where risk justifies it

• Keep external doors secure and close properly

• Consider arson risk in your fire risk assessment

12) Human factors: training gaps and unclear responsibilities

A well-designed system fails quickly if people don’t understand it.

Typical office causes

• Staff unaware of escape routes or assembly points

• Fire wardens not trained or not enough wardens for occupancy

• Poor induction for new starters and contractors

• Fire drills not carried out or not reviewed

Practical controls

• Provide fire safety training at induction and refresh periodically

• Appoint fire wardens/marshals and train them properly

• Run drills and capture learning (blocked routes, slow evacuation, confusion)

• Make responsibilities clear: who checks kitchens, who closes doors, who calls the fire service

Quick checklist: reducing office fire risk

• Keep electrics safe: no overloading, maintain wiring, manage PAT

• Control heat sources: heaters, kitchens, and appliances

• Improve housekeeping: manage waste and storage

• Protect compartmentation: fire doors, risers, fire stopping

• Manage contractors: hot works permits and fire watch

• Maintain systems: alarms, detectors, emergency lighting

• Train people: induction, refreshers, drills

• Reduce external risk: bins away from the building, security

Conclusion

The most common fire hazards in UK office buildings are usually the simplest: overloaded electrics, portable heaters, poor housekeeping, kitchen risks, and compromised fire doors. The strongest fire safety programmes don’t rely on luck—they rely on routine: clear rules, regular checks, competent maintenance, and staff who know what to do.

If you’re responsible for an office, treat your fire risk assessment as a living document. Update it when you change layouts, bring in new equipment, take on contractors, or notice repeated near-misses. Small improvements made consistently are what prevent the big incidents.

FAQs

What is the main cause of office fires in the UK?

Electrical faults and misuse (overloaded sockets, damaged leads, poor maintenance) are among the most common causes, alongside heat-producing appliances and poor housekeeping.

Are portable heaters allowed in offices?

They can be, but they should be controlled. Many businesses restrict or ban them due to ignition risk. If permitted, use approved models and keep clear space around them.

How often should a fire risk assessment be reviewed?

There’s no single fixed interval in law, but it should be reviewed regularly and whenever there are significant changes (layout, occupancy, processes, contractors, or after an incident/near miss).

Do offices need fire wardens?

Not always by name, but you do need adequate arrangements for evacuation. Fire wardens/marshals are a common, practical way to manage this.

What should we do about fire doors being wedged open?

Stop the practice. If doors need to be open for accessibility or workflow, use compliant hold-open devices connected to the fire alarm, and maintain them.

Where should external bins be stored?

Ideally away from the building and secured, so a bin fire (accidental or deliberate) can’t spread to the premises.