Water networks for collective housing: challenges, operation and sustainable solutions

Collective housing, which accounts for nearly 30% of French accommodation, has distinct characteristics when it comes to water distribution. Unlike detached houses, apartment buildings are generally connected to the public drinking water network via a single connection. From that point, an entire internal network takes over: It connects all the facilities, from the main connection to the network (the household-to-mains connection) to the points of use in each home (tap fittings, cisterns, showers, radiators, household appliances, etc.), including the equipment that is specific to each home (before-meter valve, anti-pollution check valve, pressure reducer, etc.).

It is a complex system, resembling a small network within the network, which delivers drinking water to every part of the building, ensuring that every occupant has reliable and secure access to this essential resource.

This connection consists of a public section, which extends from the drinking water supply network with a connection to the delivery point (meter and its environment) and a private section, which extends to the building’s private facilities (WC, kitchen, etc.). The public/private division principle applies in a similar way to drinking water networks that are connected to the public network.

However, this system does more than just distribute bills more fairly. It also acts as a mechanism to make occupants more responsible by making them aware of their own consumption. By having a clear and consistent picture of their usage, residents are more inclined to adopt simple measures to limit wastage: repair a leaking tap, take a shower instead of a bath, use water-saving appliances... actions which, when combined, reduce both the environmental impact and the household’s expenses.

Finally, it should not be forgotten that the smooth operation of this entire network also depends on rigorous maintenance of the installations. In collective housing, sanitation facilities are used particularly intensively, especially due to the frequent comings and goings of tenants. This makes maintenance work, and sometimes urgent repairs (such as in the event of water damage), particularly frequent.

Regular checks, preventive replacements and appropriate maintenance are essential to prevent leaks, preserve water quality and maintain comfort for occupants. This includes plumbing fixtures or wastewater systems, or even on less visible parts (meter protection, replacement of network fittings, etc.).

In France, responsibility for drinking water networks is shared and divided among several parties, depending on the type of network (public or private) and the location of the meters. There are generally three distinct areas of responsibility.

The public network and household-to-mains connection (before the delivery point)
The public water service, which is provided by the local authority or its delegated body, is responsible for the public distribution network and for connections up to the delivery point. This is typically represented by a general meter when such a meter exists. All pipes, shut-off devices and equipment located before this point are the responsibility of the water service.

The building’s internal collective networks (after the delivery point)
From the delivery point onwards, responsibility lies with the owner or manager of the building (co-ownership management, social landlord or sole owner). They oversee the operation, maintenance and compliance of the building’s internal communal facilities, such as the risers, internal distribution networks, and the protection and control devices.

Private facilities in homes (after the individual meters)
When the building is furnished with individual meters, the facilities situated after each meter are considered to belong to the private areas. Their responsibility then depends on the status of the home: occupant, co-owner or lessor, depending on the circumstances. These facilities directly supply the points of use in the home (taps, sanitary facilities and appliances).

Through its brand CLAIRE PRO Building Solutions, the Claire Group acts as a solution provider and partner for these different players. It assists sub-metering providers in the actual allocation of co-ownership charges and helps maintenance providers in the upkeep of the building’s plumbing, sanitary and heating systems and the housing units that comprise it.

Maintaining the performance and reliability of water and wastewater networks in collective housing is a major challenge, whether from an economic, environmental or social perspective.

Tackling leaks and wastage: Water losses are a persistent problem. 20% of the drinking water produced is lost through leaks. Specifically in apartment buildings, 15 to 25% of the drinking water consumed can be lost due to anomalies. That’s why it’s essential to detect and repair leaks quickly. Solutions to detect leaks and excessive consumption are of paramount importance.

Cost control: In an apartment building, an undetected leak or overlooked excessive consumption can quickly become a heavy financial burden, either for the entire co-ownership (in the case of collective billing) or directly for the residents (if individual metering is in place). It is estimated that a leaking tap can waste up to 120 litres per day, or more than 43,000 litres per year — the equivalent of filling more than 280 bathtubs (Source: ADEME, 2024). A well-designed, properly maintained and regularly monitored network not only minimises these losses, but it also helps to keep costs related to water under control and avoid nasty surprises on water bills.

Maintenance and durability of facilities: In collective housing, facilities are subject to particularly intensive use: between tenant turnover, daily wear and tear, and minor negligence, it is essential to organise effective and proactive maintenance of the equipment. This means that spare parts must be readily available, but it also means choosing reliable products made from robust, hard-wearing materials from the outset. According to industry experts, well-executed preventive maintenance can reduce maintenance costs by up to 30% compared to purely reactive management (Source: FFB - French Building Federation, 2023). Therefore, focusing on quality from the outset is an investment in the long term and avoids costly repairs.

Preserving water resources: Every litre of drinking water saved and every leak prevented directly contributes to preserving an increasingly precious resource. In France, average drinking water consumption is around 150 litres per day per inhabitant, yet a significant proportion is lost before it even reaches the tap: an average of 20% is lost in the network (Source: French ministry for ecological transition, 2023).

Fairness and user information: Sub-metering plays a key role in ensuring that costs are distributed more fairly: everyone pays according to their actual consumption, rather than according to an arbitrary distribution formula. But beyond fairness, the law now requires users to be notified as soon as abnormally high consumption is detected — an essential right to protect them from invisible leaks, which are often discovered when it is too late. By providing residents with clear, educational and accessible information about their consumption, they can gain a clearer understanding of their usage and play their part in water conservation.

Overall service performance: From production to distribution, and from collection to treatment, every link in the chain of the public water and wastewater service must strive for excellence. Network monitoring and management, ongoing diagnostics, and the reporting of performance indicators via the Report on the price and quality of services (RPQS) are tools designed to help achieve this objective.

The Claire Group provides real-world solutions to tackle these challenges. This includes everything from installing fluid metering stations (cold water and hot water) and offering systems to detect leaks and excessive consumption, to supplying the equipment needed to manage the maintenance of private areas and developing innovative solutions to monitor and control the networks. The group is committed to providing high-quality, robust and long-lasting products, and to supporting professionals in the field with its expertise and quick response times through CLAIRE PRO and its team of experts.

Supported by office-based sales representatives who are always eager to help, they offer responsive support and dependable assistance.
Together, they deliver a customised and efficient service to cater for all your specific needs.