The practice led a multi-disciplinary team to repair existing main fabric, re-programme sections of the building, modernise the auditorium, and create a three-level administrative and circulation ’girdle’. Key features include a top-lit galleria, connected to the auditorium by post-industrially detailed glass and metal bridges. The new wing allows a large section of the Roundhouse’s original facade, originally below ground on the sloping site, to be exposed for the first time. This accentuates the co-existence of historic and contemporary architecture to great effect and, with better connections to the streetscape, has heightened the Roundhouse’\'s contribution to the urban scene.

Structural interventions were minimised to emphasise the Victorian building’s structure and aesthetic. New circulation and administrative segments are thoroughly contemporary, but detailed in sympathy with the building’s original industrial soul. McAslan also increased audience and specialist-use capacity, and the building’s functional range, without disrupting key aspects of its form.

A particularly significant intervention concerned the railway turntable ash-pits in the Roundhouse’s extraordinary radial undercroft. These were cleared of tons of detritus, subjected to meticulous remedial work, and the installation of new services, access and circulation routes (without unduly disrupting the geometry of the building’s brick-built substructure). The result is the new Roundhouse Studios, for use by creative local youngsters.

There was extensive remedial work on the rafters and boarding, with a ’sprung’ acoustic mass added to the roof. This demanded a new steel upper structure, which supports a 20-tonne load from the new technical grid. The solution, by Paul Gillieron Acoustic Design, has created virtually no disruptive visual impact.

 

Of the total £30m spend, design and construction costs for the Roundhouse scheme were below £20m – a fraction of the cost of an equivalent new arts venue of this versatility. One critic described the new Roundhouse as ’one of the most radical experiments we have yet seen in cultural interaction, a venture that aims to set a model for a multicultural society.’