Household Utility Isolation + Basic Damage Control
Find the shut-offs before an emergency, know when high-level isolation is appropriate, and recognise the point where water, gas, electricity or structural damage becomes a professional problem.
Make an isolation map
GOV.UK flood-preparation guidance recommends knowing how to turn off mains water, gas and electricity. Walk the property while everything is normal. Photograph each control, label it and put the locations on the household action sheet. Different properties place them differently, so a generic diagram is less useful than your own verified map.
Water: internal stop tap
WaterSafe says the internal stop tap is commonly under the kitchen sink but may be in a utility room, bathroom, cellar, garage or under the stairs. Close it slowly; many traditional valves close clockwise. Never force a seized valve. If it will not operate, arrange repair before an emergency. External boundary stop taps may belong to the water company and should not be treated as your routine household control.
Electricity: consumer unit boundary
The consumer unit/fuse board normally has a main switch that can isolate the installation, but only approach it if the area is dry and safe. If there is water inside the consumer unit, signs of arcing/overheating, damaged wiring or standing water around electrical equipment, keep away and get professional help. Do not remove covers or work on live fixed wiring.
Gas: use the emergency route
If you smell gas or suspect a gas emergency, use the emergency number for your nation: in Great Britain call 0800 111 999; in Northern Ireland call 0800 002 001. Official network/public-service guidance says avoid flames and electrical switching, ventilate by opening doors/windows where safe, and follow the emergency operator. Turning off at the meter can be appropriate in some ordinary domestic situations, but there are exceptions; never enter a cellar or unsafe area simply to reach the valve, and do not attempt pipe/appliance repair. If anyone may be affected by carbon monoxide, get people into fresh air and seek urgent medical help; call 999/112 for immediate danger.
Contain water without creating a second hazard
After isolating water, catch drips with containers, move possessions out of the flow and protect lower floors if safe. Do not climb into unstable ceilings or reach near electrical fittings. A temporary patch is only damage limitation until a plumber or building professional can assess the failure.
Flooding
Do not walk into floodwater inside or outside the property to save possessions. It can hide holes, contamination and electrical hazards. If authorities advise evacuation, leave. When returning, assume wet electrical systems and gas appliances need checking before use. Photograph damage before major cleanup if it is safe to do so and your insurer’s process allows.
Structural warning signs
Leave and seek professional/emergency advice for partial collapse, visibly displaced walls, major new cracks accompanied by movement, sagging/bulging ceilings, unstable chimneys, doors suddenly jammed by distortion, or unusual creaking after impact/flood/fire. This guide cannot determine structural safety from appearance alone.
Ventilation and contamination
Ventilation can help drying after an incident once the property is declared safe, but do not create airflow through an active fire/smoke event or enter contaminated/structurally unsafe spaces. Flood cleanup may require gloves, boots, eye protection and public-health precautions. Utility isolation is the beginning of damage control, not permission to start hazardous repair work.
Verify / learn
These references are resolved from GPN’s central source registry so authority, coverage and source changes can be managed in one place. If a current official source conflicts with this guide, follow the current official source.
Editorial review date: 30 September 2026. Next scheduled review: 28 January 2027.