Next in line

On this new phase of Canary Wharf, however, Pelli has been restrained in his use of height, creating a group of buildings – 25, 40 and 50 Bank Street – that slot between designs by Skidmore Owings & Merrill and Kohn Pedersen Fox.

Built in the International Style, dubbed "glass-box architecture" by its detractors, 25 Bank Street will soon become home to US investment bank Lehman Brothers. At 153 m, 25 Bank Street is the same height as 40 Bank Street but its shape and position, pushing into one corner of the park, and its vast expanses of glazing give the impression that it is the taller of the two buildings. This facade mirrors the building's surroundings by day, breaking up its considerable bulk; while at night, interior lighting gives passers-by on the Docklands Light Railway a peek inside.

Pelli has physically joined these two buildings with the West Winter Garden, the first and less spectacular of two glass-covered arenas. This glass box and its arch-backed sister will feature planted areas, seating and even a restaurant, floating above the floor area on a mezzanine/bridge. The West Winter Garden also creates a dramatic gateway for pedestrians heading towards Wilkinson Eyre's swing bridge, which leads across the dock to South Quay The second winter garden, to the east of 40 Bank Street, is arched because it is taller than its counterpart. This form allows light into the lower floors of the adjoining office blocks.

To the other side of the East Winter Garden is 50 Bank Street. Whereas 40 is a tall speculative office with numerous tenants, 50 is a more squat affair, peaking at a diminutive 61.5 m tall, and home to the Northern Trust Company. But this is where the differences end. Each building is clad partly in stone and partly in glass. Light-coloured stone facades studded uniformly with windows acknowledge the 1980s buildings across the park, while the glazed side section and top to each structure lightens the overall feel and lifts each building an extra few metres.

Pelli's designs may seem safe alongside the other buildings at Heron Quays and their lobby areas definitely hark back to the power architecture of the 1980s. But this is what the powerbrokers that inhabit them want and it is what Pelli does best.

SOM goes off the grid To the westward end of the site sits 20 Bank Street, a colossal gridded box designed by SOM. The building's granite-clad grid frame structure relates to the postmodern styling of the original Canary Wharf buildings yet provides a distinct architectural statement for sole tenant Morgan Stanley.

At 68 m tall, 20 Bank Street is somewhat stunted compared with some of its neighbours. However, the granite mesh facade, broken at only one point by a seven-storey "window" that allows unobstructed light into the atrium, oozes a strength that some of the similarly proportioned glass-clad buildings on the site just can't manage.

The services core is positioned on its east side, rather than in the centre as it would be in most constructions of this nature. This shields the building from the DLR trains that run between it and 25 Bank Street. On the west elevation is the huge glazed intervention. It is described by the architect as an open outlook directed towards the city, a physical window on the world and an eye watching over London.

Refined, clinical and full of lawyers At the east end of the site, nudging its way forward to create the park boundary, is 10 Upper Bank Street, the European headquarters of law firm Clifford Chance (see page 54). Some 30 storeys – 151 m tall – this is another International Style work, although a more clinical, refined example than Pelli's versions on the site.

Designed by New York practice Kohn Pedersen Fox, this modified rectangular box is both intricate and monolithic. The result is perhaps the most sophisticated and accomplished building in Canary Wharf so far.

Adjoining the main tower is a 10-storey conference and meeting room "suite". This also contains staff facilities including a fitness centre and swimming pool. Cool white limestone adorns the lobby area, providing a distinctly different feel from the rich timber-clad interiors of Pelli's new buildings. There is a freshness and efficiency in the air, something the architect worked hard to instil with its clean interior design and open architecture.

Docklands' ghost station
There is one more new structure at Heron Quays – but it's not that easy to find. The new 84 m long Heron Quays DLR station is completely hidden under a 10-storey glass structure joining numbers 20 and 25 Bank Street.

Designed by Alsop Architects, the station is fully integrated with the two buildings and provides a link to the Jubilee Place shopping mall. The underside of the original track has been cloaked in a curving concrete shell structure, similar to the hull of a ship. This is covered in coloured, perforated metal scales, a demonstration of Alsop's trademark fusion of architecture and art. The new structure, which includes lengthened platforms and multiple escalators, is supported on metal columns and surrounds but is completely separate from the original track. Above passenger's heads, square perforated stainless steel panels present a slick styling that refers to Canary Wharf's defining feature, One Canada Square.

Alsop has created a piece of fun architecture that still manages to abide by the ethos of Britain's fastest-growing business district.