Central heating: how to split the bill fairly

In many buildings with central heating, the bill is split by ownership share: every flat pays a fixed percentage of the total, whether the radiators are on or not. For years that felt normal. Today it is one of the arguments that comes up most often at owners' meetings.

Why it turns into a row

The problem is not that some neighbours are selfish and others feel the cold. It is that very different situations coexist in the same building.

• People who live there all year, work from home or have small children, with a warm flat from October to April.
• People who are away for half the season, use the flat as a second home, or leave it empty.
• People on the ground floor, in the top flat or on the north side, who need twice the radiator to be as comfortable as the neighbour in the middle of the building.

Without consumption data, the conversation is all perception: "I hardly ever put it on" against "well, I'm still cold". Nobody can prove anything, and the meeting gets stuck year after year.

What heat cost allocators are

They are small devices fitted to each radiator that estimate how much heat it has given off over the season, based on the radiator temperature and the room temperature. Where the pipework allows it, an energy meter per flat is installed instead, which is more accurate.

One point is worth explaining clearly at the meeting: allocators do not measure euros or exact kilowatts per flat, they produce allocation units. At the end of the season all the readings in the building are added up and the real fuel cost is split in proportion to them.

And thermostatic valves

These go on each radiator and let you set a temperature per room; once it is reached, they shut off the hot water. Without them, the allocator measures, but the neighbour has no convenient way to use less. That is why the two usually come together: one measures, the other gives you the controls.

How the split changes

The bill ends up having two parts:

• A shared part, still split by ownership share: maintenance, the boiler room, inspections, heat lost through the pipes, consumption in common areas.
• A variable part, based on what each flat has used.

Make the shared part clear from day one, because the classic surprise comes from the neighbour who assumed that not switching on meant paying nothing. It does not work that way: the system is maintained whether you use it or not, and the heat from the flats next door warms yours.

How much weight each part carries is not entirely a free choice. Ask your maintenance company or a technician what the current regulations set out for your case, and put it in writing in the minutes.

Before deciding, check the rules as they stand today

In Spain there are rules on individual metering of heating consumption in buildings with a central system, with cases where it is compulsory and others where it does not apply, for example when it is not technically viable. The conditions have changed several times, so do not rely on what gets said in the lobby: ask for a technical report stating what applies to your building right now, and keep it.

What to discuss at the meeting

• Comparable quotes from two or three companies, itemising devices, installation, commissioning and the annual fee for meter reading and cost allocation. That fee recurs every year and is easily forgotten.
• How it gets paid: a one-off levy, the reserve fund, or spread over several months.
• What saving is reasonable to expect in your particular building. Ask the installer for a written estimate, not a percentage from a brochure: it depends on insulation, climate and how you use the heating.
• A simulation flat by flat: what last season's bill would have looked like under the new split. Nothing reassures people more, and it stops the feeling that some win and others lose.
• The awkward cases: ground floors, top flats, poor orientations, empty flats. Better to decide in advance whether anything gets adjusted and how.
• Who reads the devices, how often, and how each neighbour is told their consumption. Reporting during the season avoids arguments when it ends.
• What happens if someone will not allow the installation or the reading. Agree the criterion before it happens.

With allocators or without them, much of the tension dissolves when every neighbour can look up on their own what they use, what was agreed at the meeting and where the building's money goes. Keeping all of it in one place, always within reach, is exactly what we use Dommiva for, and it saves a lot of uncomfortable conversations in the lift.