SOM’s Broadgate Tower is a work of manoeuvre and negotiation, shaped by the invisible constraints of the City of London, writes Rowan Moore. Photography by Edmund Sumner
If you want to know the difference between London and Dubai, you could do worse than compare two towers that have come out of the Chicago office of Skidmore, Owings and Merrill (SOM). One, the still-rising Burj Dubai, pursues the single goal of being the tallest building in the world, without regard for such petty concerns as net-to-gross ratios or, one suspects, cost.
The Burj Dubai grows untrammelled from a vast site in single ownership – a company which happens to be owned by the emirate’s ruling family. The tower develops consistently and unhindered from its flower shaped plan to its record-breaking pinnacle.
The other, Broadgate Tower in central London, is a work of negotiation and manoeuvre; the third iteration of possible schemes on this site in a decade of project development. It occupies a plot shaped by historic vagaries of land ownership, scooped out underneath by the railway tracks heading into Liverpool Street Station.
It weaves through the web of prohibitions created by the planning system’s desire to protect views of historic buildings. Its design is influenced by an opinionated planning authority, and by the strictures of letting agents over what prospective tenants would like. It has to pay its way and stay on budget. This building is sculpted by constraints, beneath, around and above.
Broadgate Tower attains, eventually, a moment of seeming clarity – at least when seen from the south and east. It presents a clean-lined statement of structure in the style of SOM buildings of the 1950s, ’60s and early ’70s; a rectangle scored with diagonal lines of bracing like those on the 1970 John Hancock Center in Chicago. But this clarity emerges from a flurry of complexity. It is also truncated: the large, confident diamond patterns seem to belong to a building twice as high, which the architect undoubtedly would have liked.
Broadgate Tower, and its smaller companion 201 Bishopsgate, constitutes the latest phase in the quarter-century northward progression of the Broadgate development. Above all the work of its developers, Stuart Lipton and Godfrey Bradman of Rosehaugh Stanhope, the Broadgate masterplan has set precedents that have been followed by large commercial developments ever since. Places like Canary Wharf, More London, Paddington Basin and the Regent’s Place development on Euston Road, all follow its pattern.
The essential aspects of the Broadgate model are efficiently planned flexible blocks, which give corporate tenants the floorplates they want, extensive use of off-site prefabrication to give quality and efficient construction, and the creation of high-quality spaces between buildings. The latter cannot be called public realm, as they are managed privately, but they have high specifications of paving materials, coordinated street furniture, and outdoor art.
Column-free floors enable ‘flexibility, views and access to daylight that is just phenomenal’
Part of the Broadgate package was also ‘quality architecture’. Its preference was modernism, but the development has demonstrated that stylistic promiscuity is possible. Broadgate buildings treat the external skin as being apart from the frame, meaning that the skin can be given almost any appearance. They range from the spare black modernism of the first building on the site, 1 Finsbury Avenue by Peter Foggo and Arup (completed in 1984), to the pink stone lattices of the same architects’ Broadgate Square, the bombastic neo-Edwardian of SOM’s Bishopsgate Exchange (1989) and back to black-steel modernism in SOM’s Exchange House (1990), an 11-storey block held on parabolic arches above the railway lines at the mouth of Liverpool Street Station. They are all roughly the same buildings underneath, but with different stylings.
The bulk of the Broadgate development was complete by 1992, and the fact that Broadgate Tower took so long to follow is down to the complexity of the site and its relative remoteness from the most active parts of the City of London. This, by the standards of City property, is a fringe location.The tower’s site, like the rest of Broadgate, is now owned by developer British Land, which seeks to follow the principles set out by Rosehaugh Stanhope. British Land is after quality architecture, open, not-quite-public space, and efficient floor plates.
More specifically, it wanted the tower’s floors to be completely unencumbered by columns, and of relatively small dimensions. As Tim Poell, associate partner at SOM, puts it, these floors enable ‘flexibility, views and access to daylight that is just phenomenal’. They are designed to attract companies which are slightly different to the big financial institutions that occupy most of Broadgate, because it was thought culturally and commercially desirable to diversify the estate’s mixture of tenancies.
These aims, together with the engineering needed to build over the railway, shape the tower. Its lift cores and services are off-centre, rising from the solid land beside the tracks and allowing clear space in the offices. The floor plates are relatively narrow, giving a slenderness not seen in bulkier towers such as those at Canary Wharf. Without the central cores to stabilise the structure, additional bracing is needed for the glass walls, which is expressed on the exterior. There have been suggestions that this bracing, the building’s most prominent feature when seen from afar, is exaggerated for decorative effect, but SOM denies this. The big diamond patterns, the architect insists, are doing a job.
The building’s height – at 164m, the third tallest in the City of London, after Richard Seifert’s Tower 42 and Foster + Partners’ 30 St Mary Axe – is limited by both engineering issues and protected views. In particular, it had to stay out of the backdrop of the view of St Paul’s Cathedral from Richmond Park, 13 miles away. It also had to consider views of the Tower of London from the south. In fact, Broadgate Tower impinges rather more obviously on views of the cathedral’s dome from the south end of Waterloo Bridge, but the guardians of London’s vistas don’t seem to have picked this up. The tower, then, is shaped by constraints, but also serves to draw attention to the site.
Next to it, the meatier, more substantial but less conspicuous 201 Bishopsgate is a straightforward groundscraper of a type that has been slowly evolving since the 1980s, here treated with a grid of steel that frames two storeys at a time. Externally, its main interest comes from the fact that its wall follows the curve of the street, something insisted on by the City’s long-serving chief planner, Peter Rees. The curve is a minor triumph over commercial function. It would have been cheaper to build a rectangular block, in which it would have been easier to achieve what letting agents call a ‘uniform lease span’, ensuring that the distance from window to core is always the same.
Broadgate Tower and 201 Bishopsgate are unified by a glamourised industrial look, descending ultimately, but distantly from Mies van der Rohe. Steel is exhibited wherever possible, but finished with the sort of silvery grey you might find on a Mercedes.
An entrance hall leads, via doubled-up escalators, to innovative double-decker lifts
But Broadgate Tower differs from SOM’s original commercial modernism, and from the firm’s Miesian origin, in its restlessness. Where the Miesian way was to struggle for consistency in all aspects, the tower plays up the contrasts arising from its contorted site. Thus the momentary calm of the slab unravels at what is clearly seen as its back (the side facing away from the City), where lift and service towers break up the pattern of the bracing. At its base, the slab comes down on to jousting diagonal spars, which spread the load towards the embankments of the railway cutting underneath. An elaborate entrance hall leads, via doubled-up escalators, to innovative double-decker lifts that serve the tower.
201 Bishopsgate is something else again. Inside its palatial atrium, lift banks are wrapped in a Frank Gehry-esque wall of faceted glass, known as the waterfall, which cascades down the full height of the building. The building also sets itself apart from its context. Its geometry and finish contrast with the black box of Exchange House (designed by an earlier version of SOM) immediately to the south, while another SOM building, a revivalist work in orange-stained concrete that mimics terracotta, is now obscured by planting. The latter move recalls Frank Lloyd Wright’s saying that, where surgeons can bury their mistakes, architects can only grow vines.
In principle, Broadgate Tower and 201 Bishopsgate are designed to continue the Broadgate development. Earlier phases established a northward route from Liverpool Street Station that is now continued through a pedestrian-only space between the two new buildings, and heads purposefully towards the fresh air that will one day, it is hoped, contain further development. The link is reinforced by a raised table of high-grade paving that joins the new and older phases of Broadgate across Primrose Street. The pedestrian space, to be lined with the customary assortment of wine bars and coffee shops, is partly covered, and is described by Poell as ‘a modern Leadenhall Market’.
It is striking that an environment created by one practice can contain so many different formal devices – the parabolic arch of Exchange House, the faux terracotta, the diagonal struts, the Gehry-esque cascade – while retaining a consistent overall texture of high-quality corporateness. Here, architecture creates the appearance, rather than the reality of diversity.
There are, in effect, two architectures. One is what you see, which is the profusion of sometimes disjointed motifs, reflecting the office politics of SOM over the years and the changing tastes of Rees. The other is what you feel, which is the normalising development principle underlying it all, expressed as granite, steel and glass; as wine bars and coffee shops; and as an effective maintenance and security regime.
There are things to like about Broadgate Tower and 201 Bishopsgate, including the tower’s presence on the East London landscape and the air of sharpness and confidence. There are many cruder and duller office blocks around. And while the spread of not-quite-public space can be pernicious, here it is formed out of something – the air above the tracks – that was never public in the first place. Even in these days of disenchantment with big business, the corporate world still exists, and I see no point in disguising its works.
But I still wish that the distribution of sameness and difference on this site had been adjusted. The situation is inherently dramatic – tower over tracks, corporate City meets ex-industrial East End – but the drama is smoothed over by the underlying normality of the developer’s and architect’s approach, and is not brought back by the over-active architectural devices. A calmer and more coherent architecture, combined with a less generic approach to landscape and open space, could have made an exceptional place of the site’s London-esque circumstances.
Poell rhapsodises about working in London, calling it ‘one of those truly wonderful places where everyone cares about quality’, and there is certainly an intent among planners and developers like British Land to do a good job. It would be even better if this included an imaginative conception of a whole location, to which individual buildings could contribute. A plan, if you like, but a creative one.
Start on site date October 2005
Contract duration 33 months
Gross external floor area 111,480m²
Form of contract Construction management
Total cost £191 million for Broadgate Tower and £151 million for 201 Bishopsgate
Client British Land
Development manager M3 Consulting
Structural engineer SOM
Services engineer Jaros Baum and Bolles
Quantity surveyor Davis Langdon
Planning consultant DP9
Main contractor Bovis Lend Lease
Acoustics Sandy Brown Associates
Landscape EDCO Design
Speciality lighting Maurice Brill Lighting Design
Fire strategy Bodycote
Annual CO2 emissions Predicted 1,394,470kg