Brian Clarke’s painting Site Plan from 1978 was inspired by the Willis Faber building, designed by architect Sir Norman Foster between 1973 and 1974 as the UK headquarters of the insurance firm Willis Faber & Dumas (later Willis Corroon).

The painting reproduces the floor plan of Foster’s building against a gridded background and reflects Clarke’s deep engagement with modern architectural principles, as well as his growing interest in the cross motif, which he explored during the same period in his Early Cross Paintings of 1978–1979.

In 1997, Clarke returned to the subject in Site Plan II, a site-specific tapestry developed through a series of preparatory designs before reaching its final woven form.

Reflecting on Foster's building in 1998, Clarke said:

"Willis Faber is one of my favourite buildings in the world. In the late 70s I based a painting on it and have visited it countless times over twenty years."