According to the reference study by the French Directorate General for Enterprise (2024), a hotel uses 240 litres of water per person per night in the one to three star segment, and 323 litres in four and five star hotels, across all uses. The share used by the guest in the room comes to around 150 litres per night, of which at least 100 litres for the shower. A volume neither guest nor operator ever sees running, but which the property pays for twice over: the water, and the energy that heats it.
* Assumptions: water and sewerage at €4.37/m³, heating from 12 °C to 40 °C, around 0.0326 kWh per litre, electricity at €0.298/kWh, i.e. €9.67/m³ of heating. Full detail on the key figures page.
Consumption measured by public studies
| Measure | Value and source |
|---|---|
| One to three star hotels | 240 L per person per night, across all uses, of which 40 to 45% for cleaning rooms and bathrooms. Source: French Directorate General for Enterprise (Ministry of the Economy), study on water management in the tourism sector, September 2024. |
| Four and five star hotels | 323 L per person per night, across all uses. Source: French DGE, 2024. |
| Frequently cited sector average | 300 L per guest per night, against around 150 L a day at home. A figure widely used across the sector, in energy and hotel monitoring. |
| Campsites and outdoor accommodation | 183 L per person per night, of which around 70% for bathrooms and showers. Source: French DGE, 2024. |
The Molleau working assumption: 150 litres per guest per night
The 240 to 323 L measured by the French DGE cover all uses across the property, divided by the number of room nights, of which 40 to 45% goes on cleaning rooms and bathrooms. Once that share is removed, the water used by the guest personally, in the room comes out between 130 and 190 L per night depending on the segment.
Within the room, the split is heavily skewed: the shower is by far the largest use, at a minimum of 100 litres per night. It is also the most expensive, because this water is heated. Every litre of shower water avoided therefore saves both the water and around 0.03 kWh of energy.
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What makes properties differ
| Factor | Effect on consumption per night |
|---|---|
| Segment of the property | The higher the segment, the higher the consumption: better equipped bathrooms (rain showers, bathtubs) and longer time spent in the shower. Differences of two to one are common between a budget hotel and a luxury property. |
| Bathroom fittings | A standard shower head delivers 12 to 15 L/min, against 6 to 9 L/min for an efficient one. For the same duration, a shower can use twice as much. |
| Guest profile | Leisure guests (longer showers, sometimes two a day) versus business guests (short stays). Families mean several showers per room. |
| Absence of feedback | The most underestimated factor: guests do not pay for the water and cannot see what they use. With no signal, a hotel shower runs longer than one at home. |
Has your water bill gone up and you are not sure where to start? Read High water bill at your hotel: what to do?
These 150 L per night cover domestic water in the room. A hotel's total consumption per night is higher once laundry, kitchens, spa and pool are included.
How much do the showers of a 40-room hotel cost per year?
The showers of a 40-room hotel at 80% occupancy (11,680 room nights a year) cost close to €24,600 a year, water and heating included: 150 L of shower water per occupied room per day, roughly 1,750 m³ of hot water, at €4.37/m³ for water and €9.67/m³ for heating (12 to 40 °C, €0.298/kWh), i.e. €2.11 per room night. This cost stays almost invisible in the accounts, diluted between the water bill and the energy bill.
The most effective lever: making consumption visible
Reducing the flow, with aerators or restrictors, saves water mechanically but changes how comfort feels, a sensitive matter in hospitality. The other approach works on behaviour: displaying consumption in real time during the shower.
That is the principle behind the Molleaumètre, a connected water meter screwed onto the mixer tap or the shower head with a light ring (green, amber, red). Measured by sensor in the Hénéo pilot (RIVP group): consumption falls by 23% less hot water per shower, and up to 61% observed among the heaviest users, without touching flow or pressure.
Applied to the typical 40-room hotel, that comes to 403 m³ of hot water and roughly €5,658 saved a year, a net gain of about €2,780 a year after the Molleau subscription (about €6 per month per shower, set-up fee not included). The full calculation is on the water-saving solution for hotels page, and the calculator recalculates everything with your own figures.
According to the 2024 French DGE study, a hotel uses 240 to 323 L of water per person per night depending on the segment, across all uses. For the shower alone, Molleau applies 150 L of hot water per occupied room per day, or about €2.11 per room night in water and heating energy. Real-time feedback during the shower cuts that consumption by 23% less hot water per shower, and up to 61% observed among the heaviest users (sensor measurement, Hénéo pilot, 2025-2026). Source: Molleau, molleau.com, based on French DGE and SISPEA data.