Fire Safety During Building Renovation and Construction Work

Why Renovation Work Increases Fire Risk

Construction and renovation sites have a significantly higher risk of fire than occupied buildings. The combination of flammable materials (timber, adhesives, insulation), ignition sources (power tools, hot works, temporary lighting), and compromised fire detection (detectors often isolated during dusty work) creates a dangerous environment.

Fires during construction are also more likely to spread rapidly — fire doors may be propped open, compartmentation may be breached, and the normal escape routes may be obstructed.

Managing Fire Alarms During Renovation

One of the most common mistakes during building work is completely disabling the fire alarm system to prevent false alarms caused by dust and fumes. This leaves the property unprotected.

The correct approach is to isolate only the detectors in the immediate work zone — not the entire system. This keeps the rest of the building protected. Isolated zones should be clearly logged on the panel, and compensatory measures (such as a fire watch in the isolated area) should be implemented.

If the entire system needs to be taken offline for major works, a temporary fire alarm system should be deployed for the duration.

Hot Works Permits

Any work involving heat or flame — welding, cutting, grinding, soldering, use of a blowtorch — is classified as 'hot works' and carries the highest fire risk on a construction site. Before hot works begin, a hot works permit should be issued specifying the location, duration, and precautions required.

A fire watch should be maintained during hot works and for at least an hour after completion — fires from hot works often smoulder in cavities and only become apparent well after the work has stopped.

Updating Your Fire Risk Assessment

The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to review their fire risk assessment whenever there is a significant change to the premises — including major renovation work. This should happen before works begin, not after.

Your updated FRA should cover the additional risks introduced by the works, temporary changes to escape routes, isolation of fire protection systems, and the competence of contractors working on site.

After Renovation: Recommissioning Your Fire Alarm

Once building works are complete, any fire alarm components that were isolated, moved, or affected by the works must be tested and recommissioned before the building is reoccupied. For commercial premises, this should be done by a qualified fire alarm engineer who can confirm the system is fully operational and update the service logbook.

Security Red Alert can carry out post-renovation alarm recommissioning across London — as well as helping you plan your fire safety strategy before works begin. Contact us for advice.