This innovative replacement cooling and heating project at Barclays’ building, 5 Colonades, in Canary Wharf has dramatically reduced building running costs and carbon emissions, while providing outstanding indoor comfort for occupants. Energy costs have been reduced by some £255,027 a year, amounting to nearly £5000 per week. These savings will continue to accrue over the anticipated 10 to 15 year operational life of the plant, delivering total lifetime savings of between £2.55m and £3.8m. Designed and installed by Cool-Therm in collaboration with Gratte Brothers and WSP London, the replacement system is based on all-fresh air heating and cooling. This is supplied by high performance Air Handling Units (AHUs), with a combination of waterto-air heat pumps and dx cooling. Key to its efficiency is the harnessing of energy from condensing water from the cooling system for use in heating the building.