One Hotel Mayfair: a 14.4% weather-adjusted saving in the first three months
A luxury, eco-conscious hotel on Berkeley Street in central London: more than 180 nature-inspired rooms, a spa, a Michelin-star restaurant and a striking living facade of over 1,300 plants.
The challenge
Before installation the hotel's annual gas consumption was 427,458 m³, representing 392.5 tonnes of CO2 and a bill of £283,960 a year. For a hotel with robust carbon and net zero goals, that was a significant direct emission to address, and any solution had to work without new plant, downtime or risk to operations.
What we did
The V1 system was fitted in the plant room in January 2026. The installation took a total of four hours, required no downtime on the heating and hot water system, and caused no disruption to guests, the spa or the restaurant.
The result
The first three months of data show an 18% reduction in gas use. Adjusted for ambient weather, which was warmer and significantly wetter than the comparison period, the verified saving is 14.4%, worth £16,330.35 since installation. As energy prices rise, the cash saving and return on investment only grow.
How this was measured: gas consumption compared like-for-like against the previous year using the hotel's own metering, adjusted for degree days. Comparing the same periods, adjusted consumption fell from 170,714 m³ to 146,131 m³ and the cost of gas from £113,405 to £97,075. All figures exclude VAT.
The V1 system is the OH4 Energy Saving System, so client quotes and the full case-study documents refer to it as OH4.
Download the full case study (PDF)
Run a hotel or a portfolio?
Guest comfort untouched, plant untouched, savings measured on your own meters.