Individual water meters: worth fitting, and what actually changes

Fitting meters does not reduce the building’s consumption. It changes who pays for it — which is not the same thing.

In many buildings water is shared by ownership shares: a studio occupied by one person pays in proportion to its share, exactly like a four-room flat housing five. The subject therefore returns regularly, pushed by the smaller units.

Fitting sub-meters answers that perceived unfairness. But it does more than redistribute: it creates recurring obligations the building carries for decades.

What meters really change

• The allocation of the individualised share of consumption, which follows readings rather than shares.
• Visibility: an occupant who sees their consumption reduces it, at least in the first year.
• Leak detection: an abnormal reading on one flat shows up immediately.
• What does not change: common-area consumption and network losses, still shared collectively.

That last point is decisive and systematically underestimated: the gap between the main meter and the sum of the sub-meters does not disappear, it simply becomes visible. It is then shared under the applicable rules — see excess water consumption.

The full cost, not just the fitting

A project costed only on buying and fitting the meters always turns out dearer than expected. What recurs each year has to be added.

• Adapting the ducts where the supply pipes are not accessible.
• The annual reading, remote or on site, with the recurring problem of unreachable flats.
• Periodic meter replacement, their life being limited.
• Handling disputed readings, which appear in the first year.

The penultimate point often surprises: a meter estate has to be renewed, and that spending belongs in the budget from the outset. See questions to ask about the projected budget.

What gets voted, and how

Fitting meters alters the common areas and goes to the general meeting. Be careful not to conflate two distinct decisions: fitting the meters on one hand, changing the water allocation key on the other.

The second touches the allocation of charges and follows a far more demanding regime. A building that votes the fitting without addressing allocation ends up with meters read… and unchanged billing. See ownership shares and how charges are calculated.

The often more profitable alternative

Before equipping a hundred flats, a building often gains more from reading one meter: a monthly reading of the main meter. It costs five minutes a month, needs no vote, and catches common-network leaks — almost always the first source of excess.

That is the approach in spotting excess water use, and it combines well with individual heating cost allocation, which follows the same logic.

Individual meters do not lower the building’s bill: they only show where it comes from.

Track your readings with CoproHarmony

CoproHarmony records readings, tracks gaps from one year to the next and documents incidents on the water network. Create your free space.