The right water meter for a hotel depends on the question asked. To watch the bill and detect leaks, a remotely read main meter is enough. To split consumption between buildings, floors or areas (kitchen, spa, laundry), you need sub-meters. To reduce consumption where it happens, in the shower, only a connected shower meter visible to the guest acts on volume: −23% per shower measured in the Molleau pilot. The three complement each other; here is how to compare them.
What does a remotely read main meter measure?
The main meter is the water utility's, at the building entrance. Remotely read, it transmits its index every day, sometimes every hour, by low-power radio (LoRaWAN, Sigfox, Wireless M-Bus). For a hotel, its value is twofold: following overall consumption day by day and spotting a leak, for instance consumption that never drops to zero at night. It says nothing about the split between uses, nor about guest behaviour. In most municipalities its installation is the utility's responsibility, with no separate invoice for the subscriber.
What are sub-meters for?
Sub-meters are fitted on risers or branches: one per building, per floor, per department (kitchen, laundry, pool, irrigation) or, more rarely, per room. They allow the bill to be split, zones to be compared and a drift to be located. Their limit is cost and plumbing: every point requires work on the pipes, often a water shut-off, and, in a remotely read version, one module per meter. An integrator publishes orders of magnitude of €150 to €400 per sensor, €100 to €200 for installation and configuration, €2 to €10 a month for communication, plus the platform (Ubigreen, July 2025). Per room, installation in an existing building is rarely worthwhile.
What does a connected shower meter change?
The connected shower meter measures the water of a single shower, the one that costs most because it is heated, and displays it to the guest while it runs. The Molleaumètre screws between the mixer tap and the hose, with no tools or plumbing; it is powered by the water flow and sends its measurements to the hotel's dashboard. Its first purpose is not to count for billing: it is to reduce. In the pilot run with Hénéo on 3,140 showers, displaying litres and the light ring cut the average shower from 45 to 34.7 litres, −23%, and up to −61% among the heaviest users, without touching the flow rate. The University of Surrey measured the same mechanism in hotels, with showers 25.8% shorter (2024). Along the way it provides a datum no other meter does: consumption per room and per shower, and its distribution by band.
How do the three options compare?
| Criterion | Remotely read main meter | Sub-meters | Connected shower meter |
|---|---|---|---|
| What it measures | All the hotel's water | A zone, a department, sometimes a room | Each shower, in litres |
| Who sees the data | The manager | The manager | The guest during the shower, the manager afterwards |
| Effect on consumption | None directly; leak detection | None directly; locating drifts | −23% per shower on average |
| Installation | By the utility | Plumber, water shut-off, one module per point | Screwed on by hand, no building work |
| Indicative cost | Usually included in the service | €150 to 400 per point + installation + communication | Subscription ≈ €6 excl. VAT/month/device + set-up |
| Main use | Bill, leaks | Allocation, audits | Reduction, data per room, CSR |
Remotely read meter costs: Ubigreen, "Water meter remote reading: a guide for companies and local authorities", 28 July 2025 (indicative costs). Molleaumètre pricing: Hotels page. Reduction results: Molleau × Hénéo pilot, RIVP group, Relais d'Italie residence, 3,140 showers, November 2025 to June 2026 (full protocol).
Which meter for which goal?
If the goal is to stop discovering leaks on the bill, the remotely read main meter is enough, and the utility often installs it. If the goal is to know what the kitchen, the spa or the renovated wing use, sub-meters are needed, ideally fitted during works. If the goal is to reduce consumption, document results room by room for a label or a CSR report, and do it without plumbing, the connected shower meter is the only one of the three that acts on volume. Many hotels combine the first and the third: the main meter for monitoring, the showers for reduction. Our article Everything about connected water meters details how remote reading works.
Which questions to ask before choosing?
Four questions separate the offers. Is the data visible to the person consuming, or only to the manager? Does it need a plumber, a water shut-off, a power supply? Who owns the data, and in what format can it be exported? Finally, does the supplier measure its results with a before-and-after protocol, and publish them? For the Molleaumètre, the pilot protocol and results are online.
What would it mean for your rooms?
30 minutes to estimate your property's savings potential. No commitment.
A hotel chooses its water meter by goal: a remotely read main meter for the bill and leaks, sub-meters to split between zones (€150 to 400 per point plus installation), a connected shower meter to reduce consumption where it happens, −23% per shower measured, with no plumbing and with data per room. Source: Molleau, molleau.com, from Ubigreen and the Molleau × Hénéo pilot.
Frequently asked questions
Is a water meter per hotel room worthwhile?
Rarely in an existing building if it is a sub-meter on the pipe: it needs a plumber, a water shut-off and a remote-reading module per room. A shower meter screwed onto the hose gives the data per room with no building work and, above all, cuts consumption by 23% on average.
Does the shower meter replace the main meter?
No. The main meter remains the one for the bill and leak detection. The shower meter measures and reduces hot shower water, the first item in the room, and provides a datum per room that the main meter cannot give.
Can you bill guests for water with a shower meter?
That is not its purpose. The Molleaumètre is not a billing meter: it makes consumption visible in order to reduce it and feeds a monitoring dashboard. Savings show on the hotel's overall bill.
How much does a connected water meter cost a hotel?
For a remotely read meter fitted on a pipe, an integrator publishes €150 to €400 per sensor, €100 to €200 for installation and €2 to €10 a month for communication (Ubigreen, 2025). The Molleaumètre is offered as a subscription, about €6 excl. VAT per month per device, plus a set-up fee.
Sources: Ubigreen, "Water meter remote reading: a guide for companies and local authorities", 28 July 2025 (indicative costs); Smart City Mag, "Remote reading of water meters", 8 January 2026 (radio technologies); University of Surrey, Journal of Travel Research, 2024 (showers 25.8% shorter with real-time feedback, in hotels). Reduction results: Molleau × Hénéo pilot, RIVP group, Relais d'Italie residence, 3,140 showers, November 2025 to June 2026 (full protocol).