Shared water supplies in flats and converted houses

In a house with its own supply, there is usually one pipe from the street, one stopcock indoors, and one owner. In a block of flats or a house split into flats, it is often less tidy. Several homes may share one supply pipe from the street. A single stopcock in a communal cupboard may control water to the whole building. Pipes that feed your kitchen may run through the flat below.

This page explains common arrangements in general terms, and how to find out what applies to your building. It is not legal advice. Who owns and repairs which pipe depends on your lease or tenancy, the freeholder or managing agent, and the water company's own rules, and those vary.

Common arrangements

One shared supply, separate branches. One pipe comes in from the street and rises through the building as a communal "rising main". Each flat takes a branch, usually with its own stopcock where the branch enters the flat.

A stopcock on the landing or in a communal cupboard. Some flats have their own stopcock outside the front door, in a riser cupboard, or under the stairs. It may be labelled, or it may not.

One stopcock for the whole building. In some conversions, there is only one stopcock and it controls everyone's water. Turning it off affects every flat.

Separate supplies. Some conversions were given separate supply pipes when they were split. Each flat then has its own stopcock and, often, its own meter.

Tanks and boosters. Taller blocks may have storage tanks and pumps serving several floors, maintained by the building's managers.

Find your stopcock before you need it

The time to find out how your building works is before a leak. Look:

• under the kitchen sink and near where pipes enter the flat;
• in a cupboard by the front door, a utility cupboard or an airing cupboard;
• on the landing, in a communal riser cupboard or a meter cupboard;
• in the basement or ground-floor plant room.

Find a leak and the stopcock explains how to recognise and turn one. Stopcocks and water meters covers outside stopcocks and meter chambers. Ask your landlord, freeholder or managing agent for a plan or a note of where each valve is, and which flats each one controls.

Whose pipe is whose

There is no single UK-wide rule that settles who owns every pipe in every building of flats. In general:

• The lease or tenancy usually says which parts of the building each flat is responsible for, and which are shared. Pipes serving only one flat are often treated differently from pipes serving several, but the wording of each lease decides.
• The freeholder or managing agent usually looks after communal parts, which can include a shared rising main or communal tanks.
• The water company owns and maintains its pipes up to a point set by its own rules, and has its own policies on shared supply pipes. Check with your water company.
• Tenants usually report leaks to their landlord; tenant vs landlord plumbing repairs covers the general picture.

If you are not sure, ask in writing and keep the answer.

A leak in a communal pipe

If water is coming from a pipe you think is shared, or from the flat above, act quickly but do not assume it is yours alone to deal with:

1. Turn off your own stopcock if the leak is inside your flat on your side of it.
2. If the leak continues, or is on a shared pipe, contact the freeholder, managing agent or landlord at once. Many buildings have an emergency number.
3. If a communal stopcock needs to be turned off, it may affect neighbours. Where it is safe and the building's arrangements allow, tell them. Some communal valves are locked or meant to be operated only by the managing agent or the water company.
4. If water is near electrics, keep away from the switches and get a qualified electrician. We do not give wiring instructions.

A leak in a communal pipe is not always the flat-holder's to isolate alone. Ceiling leak from above covers what to do when water is coming through from upstairs.

Insurance

Buildings insurance in a block is often arranged by the freeholder, while contents insurance is each occupier's own. Leak damage can involve both, plus a neighbour's policy. Report it promptly, take photos and keep a record of who you contacted and when. Leak insurance claims covers the process.

Lead and old shared pipes

Older buildings may still have lead in a shared supply pipe. Replacing your part alone may not remove lead from the supply. Talk to the freeholder and the water company. Lead pipe replacement explains how to spot lead and who to contact.

Low pressure in flats

Upper floors in a block may have lower pressure, and fixtures used at the same time in several flats can make it worse. If it is a building-wide problem, raise it with the managers rather than fitting a pump in your own flat without asking. Any pump on the supply may need permission, and the lease may require consent for alterations.

Who is responsible for the stopcock in a block of flats?

It depends on the building. A stopcock serving only your flat may be yours to use, while one serving several flats is usually managed by the freeholder or managing agent. Check your lease and ask the managers.

Can I turn off the water for the whole building?

Only in an emergency, where it is safe and the building's arrangements allow, and tell the managers and neighbours straight away. Some communal valves are locked or reserved for the managing agent or water company.

My water comes through a neighbour's flat. Who fixes a leak on it?

It depends on the lease and whether the pipe serves only you or several flats. Contact the freeholder or managing agent, and your water company if the pipe may be theirs.