Doors and windows

The east elevation of Fort Dunlop, Urban Splash’s office, retail and leisure scheme in Birmingham, is clad in glass. In the rest of the building, the glazing sits 1.5 m behind the retained brick facade

How do you turn AN unappealing former tyre factory into a landmark building that will attract hordes of shoppers and office workers? That was the challenge faced by Liverpool architect Shed KM when it took on Urban Splash's £40m Fort Dunlop scheme in Birmingham. Just a year ago, drivers speeding past the 6500 m2 site on the M6 would have only glimpsed a collection of broken windows. Now those windows have been replaced by a glass skin that sits behind the original brick facade. If drivers were to leave the motorway, they would find a totally revamped building that will house retail, office and leisure space when it is completed later this spring.

The solution adopted for the windows is part of the strategy to create a glass box structure within the existing building. This monumental project required more than 6000 m2 of glass - the equivalent of a football pitch - and 1360 individual glass panels.

The original brick building, which was erected in 1906 for the Dunlop rubber company, closed down in 1980 and had since fallen into disrepair. It is a locally listed building, but according to Hazel Rounding, lead architect on the project, it hasn't had a real identity for the past 25 years. Rounding says: "The former windows were flat and dull. In creating a new life for Fort Dunlop, we wanted to symbolise the changed use for the building through a series of striking architectural statements that also deliver practical benefits."

On each of the building's six storeys, the project team installed full-height double glazing that stands 1.5 m behind the brickwork. Because the architect wanted to create a completely frame-free glass wall, the glass panels are linked with a silicon joint to achieve a seamless effect.

To further the sense of a crystal cube within the building, all the bricks in the east elevation were replaced with glass. The architect also designed an extension above the sixth floor that is entirely clad in glass.

"We wanted to take a bold move and the consequence of that thinking was to turn the existing facade into a relic," says Rounding. To preserve most of the original building, masonry repair work was conducted on the windows to reveal their original features. The architect had previously used an internal glass wall for a grade II-listed residential scheme in Liverpool. The project was not as radical as Fort Dunlop but it offered a model for future schemes. "Rather than detract from the existing building, it is better to leave it there and treat it like a relic," says Rounding.

The 1.5 m gap between the window frame and the glazing is not only intended to maximise the amount of natural light in the building. The acoustic and air-conditioning systems have been installed in the gap to avoid spreading them all over the building. The double-glazed envelope also acts as an efficient thermal and acoustic insulation solution.

Thanks to this innovative combination of conservation and refurbishment, Fort Dunlop seems set to redefine the traditionally lacklustre image of business parks.

More than 6000 m2 of glass was used to create a clear box inside the 1906 building. The glazing goes floor to ceiling, with silicon joints between panels to create a seamless effect. Acoustic and air-conditioning systems have been placed in the gap between the brick and the glass