Water management holds an important place in the main sustainable tourism standards, and cutting hot water volumes can also contribute to the energy targets of properties covered by French energy regulation. One caveat: these frameworks do not impose the same obligations. Some assess water management, while the French Éco Énergie Tertiaire scheme covers final energy consumption.
Green Key
Green Key is the leading international sustainable tourism label for tourist accommodation and restaurants. Run in France by the Teragir association, it counted 3,035 certified properties in 2026.
Its standard comprises around 120 criteria across seven themes, one of which is water management. Properties are expected to monitor their consumption, limit flow rates, install equipment that reduces usage and comply with the rules on wastewater. The standard distinguishes mandatory from recommended criteria, within a logic of continuous improvement.
Detailed room-level measurement, while not required by the label, is a genuine asset: it complements main-meter monitoring, reveals the heaviest-consuming rooms and proves the results of the actions taken, with figures to back them up. Useful material for both the application and the renewal audits.
Green Globe and GSTC criteria
The Green Globe standard comprises 44 criteria and more than 400 indicators, adapted to the property's activity and location. Certification is renewed annually, on the basis of a continuous improvement commitment verified by independent audits (Gold status is awarded after five consecutive years of certification, Platinum after ten).
The international criteria of the Global Sustainable Tourism Council (GSTC) require, among other things, that water consumption be measured, that reduction targets be set and that guests and staff be engaged. Indicators expressed per night or per occupied room can be used to track performance over time.
Continuous measurement, room by room, gives you a finer level of analysis to manage consumption and demonstrate progress.
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French energy regulation: acting on hot water means acting on energy
The French Éco Énergie Tertiaire scheme applies to buildings, or groups of buildings, housing service-sector activities across at least 1,000 m². It requires final energy consumption to fall by 40% by 2030, 50% by 2040 and 60% by 2050 against a reference year, with an annual declaration on the OPERAT platform.
The regulation sets no water reduction target: it covers energy. But cutting hot water volumes saves the energy needed to produce them. Heating a litre of water from 15 °C to 40 °C theoretically requires around 0.03 kWh, before production and distribution losses. Hot water savings can therefore contribute to a property's energy trajectory where that energy falls within its declared scope.
CSRD and sustainability reporting
Where a group identifies water as a material issue in its CSRD reporting, the ESRS E3 standard may require it to publish the volumes consumed and the methods used to establish them. The texts permit direct measurement, but also calculations, modelling and documented estimates. Sensor data therefore improves the accuracy, traceability and frequency of reporting, without being mandatory in every case.
What the Molleaumètre contributes
The Molleaumètre measures the volumes used during showers, room by room, and sends the data to a dashboard: consumption tracking, comparison between periods, conversion into euros and CO₂, and exports for your audits. According to the results of the Molleau x Hénéo pilot (RIVP group), run in 2025-2026, real-time feedback during the shower cut consumption by 23% per shower, and by 15.5% on the residence main meter (up to 61% among the heaviest users), with no change to comfort. The full approach is described on the water-saving solution for hotels page.
Green Key and Green Globe both give significant weight to measuring and reducing water; French energy regulation covers final energy, to which hot water reduction can contribute. In every case, sensor data strengthens management and traceability of results, without replacing the other elements labels or regulation require. Estimate your potential with the Molleau calculator.
Sources: Green Key standard (Teragir); Green Globe and Global Sustainable Tourism Council (GSTC) criteria; the French Éco Énergie Tertiaire scheme and OPERAT platform; ESRS standards under the CSRD directive. Reduction results: Molleau x Hénéo pilot, RIVP group (2025-2026).