Set within Mayfair's 'French Quarter' - so-called because of the prevalence of steep mansard roofs - this new office building needed to be sympathetic to the distinct character of this conservation area, and yet still make its own architectural contribution. Issues of scale, materials and solidity in relation to the streetscape had to be addressed in order to satisfy both English Heritage and Westminster planners.

As a result, the design is based on a modern re-nterpretation of the neo-classical architecture of its listed neighbour, Devonshire House. Its form and elevation adhere to the classical ordering device of base, middle and top, while clearly articulating the stone cladding and windows into bays in a contemporary way. The 'base' is two storeys high with Portland stone columns and projecting bay windows capped by a stone cornice. The 'middle' section is three storeys high with balconies and metal louvres for solar shading supported from continuous vertical steel members.

The 'top' integrates the whole facade with its seemingly traditional, zinc-clad mansard roof that in fact conceals three more levels of office space and uses very modern detailed design. Double-height openings within the roof cleverly reduce the apparent mass and allow unbroken fenestration to run behind. This overcomes the 'garret'-type feel often associated with mansard roofs and has resulted in increased rental value for this space. To complete the composition, the roof plant is contained within five discrete acoustic attenuation enclosures, reminiscent of the large chimneys of the nearby Ritz Hotel.

Viewed from the street, the elevations appear to be relatively solid, but in fact provide large floor-to-ceiling windows. These create a light and airy feel inside, while complying with the planners' request of no more than 50 per cent of the elevation being glass. The internal planning is very simple with a centrally placed entrance and core that allows for subdivision. From the scenic lifts, positioned in a lightwell to the rear of the building, can be viewed a wall of black marble animated with water and light which adds drama to the space, especially after dusk.

Client: Burford PLC.