St James Square contains some of central London’s most valuable real estate. No 31 is significant by virtue of its history (it was previously the site of the Duke of Norfolk’s royal residence, and its 1938 replacement, though unloved, became Eisenhower’s HQ during WWII) and by the fact that it is ‘L -shaped’ on plan, with a second prime façade on Charles II Street. However, notwithstanding its heritage and location, its workspace was tired and outdated and we were commissioned by the freeholder – The Brunei Investment Agency – to consider its replacement, with a predominately new-build office scheme, using an alternative use – potentially an art gallery – at ground and lower ground floors, to offset what would otherwise be a non-compliant uplift in B1 office space. The existing building had been subject to a London Building Act requirement to limit its facade height to 80’, and the impact was to dramatically reduce floor/floor heights. Our replacement sought to offset this with a set-back top floor within a restrained contemporary brick principal façade.