40 Grosvenor Hill is a small office building in Mayfair, located in what would originally have been a Muse area, behind buildings facing onto Grosvenor Street. Located in a conservation area, the design of the building was very much dictated by Town Planning requirements, which resulted in the retention of the facades of some of the original buildings. The planners aim was to simulate the small-scale buildings of the area in the new scheme, which brought a number of small buildings together in a single office building.

There are various views about such a design approach, but development behind retained facades is a very common feature of the historic areas within London and particularly in the City of Westminster. The design constraints on 40 Grosvenor Hill were very onerous, but resulted in an interesting building. Grosvenor Estate was sympathetic to the view that the building should incorporate as far as possible a low energy design principles and consequently it incorporates ground source heating and cooling.