Playing with Sunshine

By Teresa Simon

Photography: Nigel Young; Hufton & Crow; Courtesy: Foster+Partners

Foster & Partners incorporate ambitious environmental strategy in a new sculptural addition to the city of London…

Wrapped in a grid of highly reflective cast-aluminium brise soleil, shimmering in the bright sunshine, casting intriguing chiaroscuro effects on the street side, the Walbrook office building stands tall, distinctly individualistic, yet contextually alluding to the historical fabric of its neighbourhood.

.

.

The form of the building is designed to minimize the apparent mass of the scheme when viewed from the street and to increase the opportunity for daylight to reach the surrounding area. Its rippled facade lends it a texture that exposes the structure – column casings are revealed and the grid of the building is expressed externally. The blades of the brise soleil grow in density as they rise higher, responding to the increasing requirement for solar shading, reducing the amount of cooling required to the office interiors. Made of a glass-fibre-reinforced polymer – a material more commonly used in the bodywork of cars – the louvers wrap the entire building, unifying the main volume with the receding upper levels, so that from the street the facade appears as a continuous arc. The facade is articulated as a series of bays, which refer to the domestic scale of the buildings that originally stood here and have the effect of extending the site boundary to optimize the plan area.

.

.

The sculptural and reflective qualities of the project continue inside, with two curved full-height atria carved out of the deepest sections of the floor-plate, elliptical on plan, linking levels three to nine. Each atrium contains bridges connecting through to the glazed passenger lift lobbies. Linked by the lift lobby, the atria draw daylight deep into the building. The social areas – including the entrance foyer and the lift lobbies – are lined with low-ion fibre-optic glass tubing, creating a brilliant illuminated ribbed surface that also forms part of an energy efficient lighting strategy. The lifts are fully glazed, adding to the play of light and reflection.

.

.

The challenge in designing any new commercial structure in the city of London is to create a building that can both acknowledge its historical context and stand discreetly on its own terms. The Walbrook replaces an undistinguished group of 1950s offices within the city’s conservation area. The structural framework in steel makes a contemporary statement in an area where planning guidance has traditionally favoured the use of stone. Added to the photovoltaic cells, renewable systems such as tri generation and rainwater harvesting are also implemented.

.

.

The building is rated “Excellent” under BREEAM, the world's foremost environmental assessment method and rating system for buildings.

.

.