The 69,000m2 Willis Building comprises a 29 storey tower and an adjacent 10 storey office building. With a full appointment for the design of the mechanical and electrical services on the development, Grontmij’s main objective was to provide an environmentally conscious ‘world class’ building.

Future proof
The development has CO2 emissions far lower than the maximum allowed by the UK Building Regulations at the time of design. The design was also "future proofed", even surpassing the requirements of the most recent UK Building Regulations by some 20%.

Working in close collaboration with architects Foster & Partners, a number of environmental measures were incorporated into the building. This includes a super efficient façade to reduce solar gains (and therefore cooling requirements of the offices) whilst maintaining daylight levels and spectacular views.