Facade, Preston

This remarkable design for an office building in Preston, UK, is the winner of a Royal Institute of British Architects (RIBA) competition, held in 2007. The 3720-square-metre building is four storeys high. It includes large open-plan office floors and a full height atrium/exhibition space. The building has been designed for a confidential commercial client. Last autumn Moxon has submitted a planning application for this project.

Ben Addy, practice principal at Moxon, describes the unusual design as 'a pragmatic response to the brief'. 'There was a limited budget to create a prominent building with flexible, naturally lit office space,' he explains. 'Therefore, a glazed facade with a brise soleil was the answer. This different solution to the shading was inspired by movement: the sun's trajectory and the passage of traffic past the building.'

The £7 million building is to be built on the intersection of a busy main road. Moxon's design envisages passers-by experiencing it as an animated object as they move towards and obliquely past it along the carriageways. 'By turns, the building appears solid and then transparent depending on the viewer's position: it reveals the interior and then morphs to hide it again,' says Addy.

The facade system includes over 2000 anodized aluminium fins up to 2.5 m in length, which are bolted to tensile steel rods on all four sides of the building. In turn, these rods are fixed to horizontal beams at each floor level. The fins sit 800 mm away from the glazed facade to allow for cleaning and maintenance. 'Contrary to its appearance, there are no unique, costly elements to the facade,' says Addy. 'Repetition and mass production is the key to the facade's manufacture and its appeal to me. The horizontal fins are a simple, cost effective shading solution that also presents a striking aesthetic. As you move around the building it changes from a solid shape to a transparent object in varying degrees.'

On the south-west facade, the longest fins act as a large-scale brise soliel and rain screen, but on the south-east wall they appear more visually permeable. To the northerly aspects they are shorter, allowing in maximum light. High summer sun is excluded so as not to affect the environmental conditions within the building but early morning and winter sunlight passes through the facade to provide what the RIBA competition judges describe as 'an extraordinary quality of light'.