Empire building

To Wilkinson Eyre Architects, the early 1960s Empress State Building has a certain James Bond glamour about it. Though perhaps not quite in the Aston Martin class, the 30-storey tower in south-west London flaunts a shapely form.

Built to a Y-shaped plan, its curtain walls curve sexily between three stone-clad corner towers.

Hammersmith & Fulham's planners share Wilkinson Eyre's fondness for the prominent building and regard it as one of the few landmarks in the borough. Indeed, it was they who led to the appointment in April 2001 of the double Stirling prize-winning architect to refurbish the building. For three years up until then, the heavyweight developer, Land Securities, had floundered with a sequence of planning refusals.

"We've been sympathetic to the building without being retro," says Wilkinson Eyre director Paul Baker. For LandSec, this respectful yet contemporary approach paid off, as the architect won full planning permission within seven months of its appointment. This week, the developer formally launches its marketing drive to lease the office building after its £76m facelift.

The 40-year-old building came with its share of problems. The curtain walls needed renewing in a more energy-efficient system and the natural ventilation system had to be replaced with modern air-conditioning. In addition, LandSec wanted to increase lettable floor space and add a clutch of communal amenities for tenants as part of its new serviced office concept, Landflex.

Earlier refurbishment schemes had solved the technical problems and extended the narrow floorplates by the crude expedient of enveloping the entire building in a new outer skin of curtain walling. Wilkinson Eyre, on the other hand, noted that the three corner cores sported elegant, finely detailed patterns of windows and two-toned stone panels. So the architect was careful to replace the existing expanses of curtain walling without encroaching on the stone corner cores.

The south facade was singled out for special treatment. It was extended outwards by 5.5m to expand the floorplates. In addition, the new window wall was overlaid by an external screen of horizontal aluminium louvres that act as a sun screen without obstructing views out of the building. At either side of the extended floorplates, the new curtain wall returns neatly to meet the stone corner cores' inner edges.

At the top and base of the tower, bolder interventions have been made by Wilkinson Eyre. The base has been expanded to form a wide two-storey drum that contains an enlarged entrance hall, staff restaurant and plant rooms.

The top of the tower originally terminated in a weak, abrupt manner with a squashed penthouse floor, surmounted by a lopsided arrangement of an observation room and plant storage. These have all been replaced without raising the height of the building. Three new office storeys have been built behind a transparent, outward-sloping window wall and beneath oversailing eaves. And tenants can get their Martinis shaken (not stirred) in the revolving bar in central coronet above.

As well as providing more usable floor space, the new top three storeys and coronet give the tower the emphatic lid that it lacked before. What's more, the penthouse restaurant, with its spectacular revolving panorama of London, offers the occupants a generous measure of Bond-like glitz.

In front of the tower, what was once a sea of car parking has been transformed into an attractive pedestrian piazza with patterned paving, seats and trees. The piazza is bounded by new two-storey strip buildings that contain a fitness club, crèche, bar and convenience store for tenants, while also forming a buffer to shield the development from the neighbouring houses.

In refurbishing this 1960s tower, Wilkinson Eyre has managed to increase floor space by 26%, add modern services and a wealth of social amenities and at the same time make it more glamorous inside and out. Little wonder that Landflex is marketing the building with a CAD image of a broad-shouldered, tuxedo-clad, enigmatic male figure staring out of the revolving penthouse restaurant.