Spanning two mews behind Grosvenor Place and Belgrave Square, the initial analysis recognised the opportunity as ‘a great location but a terrible site’. The site was ‘unlocked’ by creating a new walled garden within which is one of London’s best residential developments. The ‘address’ is created by taking the front doors off the mews and putting them in a courtyard garden behind a beautiful wall, designed by artist Andrew Goldsworthy. An imposing and heavy entrance gate sits in a portico that punctures the slate wall and leads to a colonnade that dissects the city block to link the two mews. The living accommodation is situated around a floating garden, and above the colonnade rises a simple background architecture (a big box), in front of which project ‘floating walls’ of loadbearing stone. Between the two are located balconies, glass boxes and terraces. The approach to the architecture is driven by the material – a loadbearing limestone with 3mm joints. This gives the simple language quality and substance while co-ordination of elements is controlled by a modular proportioning system. The result is seamless detailing and a calm, effortlessness to what is a very complex building. The detailing of the interiors is equally controlled with carefully concealed services and home automation.