When a fire occurs, the investigation process determines cause, origin, and responsibility. We explain the UK fire investigation process and its role in improving building safety.. The Investigation Process Phase 1: Scene Examination Origin determination — identifying where the fire started Cause determination — identifying what started the fire Evidence collection — physical samples, photographs, witness statements Phase 2: Laboratory Analysis Accelerant detection using gas chromatography Electrical fault analysis Material identification and failure analysis Phase 3: Reporting Expert report for criminal, civil, or insurance proceedings Compliance assessment — did the building meet regulations? Recommendations for prevention Common Fire Causes Found 1. Electrical — overloaded circuits, faulty appliances, damaged wiring 2. Cooking — unattended cooking, fat fires 3. Arson — deliberate fire setting 4. Smoking — discarded cigarettes and vaping devices 5. Equipment — industrial plant, HVAC systems Lessons for Fire Engineers Fire investigation findings directly inform: Fire strategy design decisions Risk assessment methodology Product specification and standards Evacuation strategy validation For expert fire investigation and witness services, contact Magnus Opifex.