Does my block's communal boiler need registering with Ofgem?

If heating or hot water comes from a shared source and the building is divided into separate flats, almost certainly yes. The deadline is 26 January 2027.

What counts as a heat network

Ofgem regulates any system that supplies heating, cooling or hot water from a central source to more than one property. In a single building divided into flats, Ofgem calls this a communal heat network. Where one source serves two or more buildings, it's a district heat network. Both must be registered.

Signs your block is one: a communal plant room or boiler house, heat interface units (HIUs) in each flat instead of individual boilers, or a connection to a local district scheme.

Who owns the flats doesn't matter

A communal heat network is one that supplies a single building divided into separate homes. It doesn't matter whether the flats are sold on long leases, let by a private landlord, or owned by a housing association or council. All of them are in scope unless an exemption applies.

Buildings that are exempt

• A building converted into flats that is heated by no more than one appliance of 45kW thermal capacity or less
• A single house in multiple occupation (HMO) with shared kitchens or bathrooms and shared heating. Buildings converted into self-contained flats aren't covered by this exemption
• A building with shared facilities that isn't divided into separate homes, such as a care home
• A communal system that only provides air conditioning and no hot water

What to do if your block is caught

Existing networks were authorised automatically when regulation began on 27 January 2026, but they still have to be registered with Ofgem's digital service by 26 January 2027. The first step is working out who the operator and supplier are.