Individual Water Meter: Apartment Billing and Leak Costs

When water is billed at the building level, three different arrangements coexist in France, and knowing which one applies to your home changes how you read your service charge statement. Either a single main meter serves the entire building and the building manager allocates the bill according to each owner’s co-ownership shares, or submeters measure each home’s consumption while the building manager remains the sole customer of the water utility, or each occupant has an individual contract and receives a personal bill, as they would in a house. The following explains how to identify your situation, how your share is calculated, why a leak that is not in your home can still drive up your bill, and what to ask your building manager for to check your charges.

• Your water bill depends on your building’s arrangement: one main meter, submeters, or individual contracts, each with its own allocation method.
• An excess between the main meter and the total of the individual meters is legally treated as common consumption, billed to everyone according to their co-ownership shares rather than assigned to a single home.
• Paying for water use and paying for repairs after a leak are two separate mechanisms: the latter depends on where the leak occurred, with the IRSI agreement providing a framework for settling claims between insurers in some cases.
• Regularly noting your own meter reading lets you check the building manager’s statement and spot a private leak early.

How water costs are allocated in a multi-unit building

Before looking into why your bill has changed, you first need to know which of these three arrangements applies to your building, because the calculation method is completely different in each case.

• One main meter serves the entire building. This is the most common arrangement in older buildings: the building manager receives a single bill from the water utility and allocates it among the co-owners according to their co-ownership shares—that is, their share of ownership in the building—with no direct connection to how much each household actually uses.
• Submeters, one for each home, measure each apartment’s own consumption, but the building manager remains the sole customer of the water utility: they receive the single bill and then use the individual readings to allocate each home’s personal consumption. Water used in the common areas is still allocated according to co-ownership shares.
• An individual contract goes further: each occupant becomes the direct customer of the water utility for their own home and receives a personal bill, as they would in a detached house.

The annual service charge statement sent by the building manager normally indicates which of these three arrangements applies. If in doubt, the question to ask is simple: who is the customer of the water utility—you personally or the co-owners’ association?

Is an individual water meter required, and since when?

The answer depends mainly on the age of the building. New buildings must have an installation that measures the cold water supplied to each home and to the common areas, an obligation set out in the French Construction and Housing Code (source: Article L152-3 of the French Construction and Housing Code). Buildings constructed before this requirement came into force are not required to retrofit, and many still operate today with one main meter allocated according to co-ownership shares (source: Notaires de France, on the legislation governing water meters in co-owned buildings).

A third option—the individual contract described above—has existed since the SRU Law of December 13, 2000 (Article 93): a building owner can ask the water utility to provide individual supply contracts, provided occupants are first given full information about the technical and financial consequences of the change (source: ANIL, on individualizing cold water supply contracts).

How the building manager calculates each home’s share

Each year, or as often as specified in the co-ownership regulations, the building manager brings together two items: the single bill sent by the water utility and the individual meter readings. Consumption in common areas—cleaning, outdoor taps, watering the garden—is separated out and allocated according to co-ownership shares rather than meter readings, since no one has an individual meter for these shared uses (source: Notaires de France, cited above).

Example: how a shared water bill is broken down

Let’s take a purely illustrative example, unrelated to any real building. A total water bill of €3,000 for the year, compared with €2,400 in total on the submeters: the remaining €600 counts as common consumption and is allocated according to co-ownership shares, in addition to each home’s share based on its own meter. So the final amount paid depends on two factors, not just one.

Why the difference between the main meter and individual meters matters

In a building equipped with submeters, the main meter sometimes records a greater volume than the total shown by all the individual meters. This difference is not a billing error: case law treats it as water needed to maintain the common areas, for example a slow leak in a shared pipe, and it must therefore be allocated collectively among all co-owners according to their co-ownership shares rather than assigned to a specific home (source: Kohen Avocats, on allocating and disputing water meter charges in co-owned buildings, citing a January 2016 ruling by the French Court of Cassation). This rule explains why a leak in a shared pipe can drive up the bill for all occupants even if none of them has changed their water-use habits.

A co-owner who wishes to challenge how a general meeting allocated water charges has two months from receipt of the minutes to do so, after which the decision becomes final (source: Kohen Avocats, cited above). This question of allocating consumption is separate from the question of who pays to repair the leak itself, which the next section explains.

Leak in a neighbor’s home or a shared pipe: who pays for the damage?

A leak in a neighbor’s private plumbing is the responsibility of that occupant and their insurer, whereas a leak located in a common area—a riser, roof, or façade—is the financial responsibility of the co-owners’ association, which covers the leak detection and repair (source: Kohen Avocats, on the IRSI agreement and water damage in co-owned buildings).

To settle these claims between insurers, the IRSI agreement, in force since June 1, 2018, sets out a tiered framework: up to €1,600 excluding tax, the affected occupant’s insurer pays directly with no right of recourse; between €1,600 and €5,000 excluding tax, a fixed-scale recourse arrangement applies between insurers; above that amount, the agreement no longer applies and the standard rules of liability apply again (source: Kohen Avocats, cited above). This is an agreement between insurers only and cannot be imposed on a co-owner or occupant: they retain all their rights to compensation under the standard rules for repairs, lost rent, or loss of enjoyment. The question of who pays to repair a leak and the question of allocating water consumption discussed above therefore remain two separate mechanisms, even when both are triggered by the same incident.

Reading and monitoring your own meter

In a building equipped with submeters, yours is usually inside your home, near the water inlet, or sometimes in a shared service duct on the landing. The building manager, or the contractor they appoint, usually reads it once a year to prepare the annual statement.

Noting the date and reading on your meter yourself, even informally, lets you check the building manager’s reading and spot a discrepancy before it becomes a dispute over the service charge statement. A reading that rises much faster than usual, with no change in your own habits, is generally the first sign of a private leak—a toilet that keeps running or a dripping tap—to check before assuming there has been a billing error.

What to ask your building manager

Three practical questions can help you check that your share of the water bill is consistent with the building’s actual use.

• Ask for the full annual water bill from the water utility, along with details of the individual readings used to calculate it, rather than just the final charge listed on your statement.
• Ask how the difference between the main meter and the total of the individual meters was explained for the year in question, and whether the shared pipe was inspected.
• If your home has its own accessible water shutoff valve—this is not the case everywhere, as some buildings have only one valve for the entire building—it may be useful to know about devices that can monitor this line and shut it off in the event of abnormal flow. How this type of detector works does not replace checking the allocation of charges discussed above, and it only acts on the line to which it is connected.

According to the manufacturer’s description, this type of device continuously monitors the flow on the line where it is installed and closes its integrated motorized valve when abnormal flow is detected, sending an alert through a mobile app. It does not guarantee that water damage will not occur and does not change how the co-owners’ association allocates shared consumption: it only responds to abnormal flow on its own line. Other equipment is installed in the same place, such as filtration systems installed upstream of the entire house.

The same issue arises elsewhere, with different local rules

Allocating a building’s water bill among its occupants is a common issue in multi-unit housing across much of Europe, but the specific rules—who must install a meter, who remains the water utility’s customer, and how disputes are settled—are set by each country’s housing and insurance framework. The mechanisms described here—co-ownership shares, the SRU Law, and the IRSI agreement—are specific to French law and should not be applied elsewhere as they are.

Your water bill therefore depends on your building’s arrangement, the difference between the main meter and the individual meters represents a common charge rather than an error, and who pays for water use is separate from who pays for repairs after a leak. With these points in mind, you can ask your building manager for the right documents and understand what your service charge statement actually means. For more practical guides to water at home, browse the blog index.