Hardly square
GRID
24/05/03
No 1 Spinningfields Square had to give a futuristic lead to office regeneration in Manchester. Architect Sheppard Robson was up to the task. David Quinn reports
On 15 June 1996, a bomb concealed in a van demolished a swathe of Manchester city centre, setting in motion a period of rebuilding and regeneration that is still proceeding. But the construction of retail schemes close to the site of the blast on Cross Street has largely been completed and has propelled Manchester into the superleague of UK shopping destinations.
Regeneration efforts have now switched to the provision of first-class offices to accommodate blue-chip occupiers, which are keen to expand into the revived city.
Spinningfields, a 3m sq ft, mixed-use scheme covering 50 acres between Deansgate, Quay Street, Bridge Street and the River Irwell in central Manchester, is one of the largest and most important development sites in the UK. As well as new public squares, restaurants and shops, the scheme will eventually boast 2m sq ft of offices.
Within the scheme, which was unveiled in 1999, the site of the building now known as No 1 Spinningfields Square is arguably the standout plot. Fronting Deansgate in a site adjacent to the Grade-1 listed John Rylands Library, it is highly visible and acts as a gateway to the scheme from Manchester’s existing business core.
However, construction could only begin once a prelet was achieved. This came at the end of 2001, when Royal Bank of Scotland agreed to take 470,000 sq ft at Spinningfields, including the 123,000 sq ft (11,430m2) building that became No 1 Spinningfields Square.
Concept architect Sheppard Robson was already working with RBS. The company’s Tim Evans, who oversaw preliminary aspects of the building’s design and construction, says the primary concern was finding a design which both the bank and developer Allied London would find acceptable. “We analysed the historical context of the site and, after speaking with English Heritage and the local planners, we decided to go with a design that was in contrast with John Rylands library,” he explains.
“The aim was to represent the future of Manchester, its international business aspect and to act as a foil to the surrounding history,” Evans adds.
Both RBS and Allied London were pleased with this approach and gave it the go-ahead, as did the planners.
Allied London, in particular, wanted the building to have high internal and external specifications. Chief executive Mike Ingall says that this is crucial to the company’s strategy for Spinningfields, in that a high quality building could act as an advertisement for the rest of the scheme.
Strategic view needed
He concedes that the same rent could probably have been achieved had the building been more “ordinary”. But he adds: “We have a wider development to consider and have the luxury of looking at things strategically. We are prepared to compromise on short-term profit to get better long-term value.”
The decisions made about the futuristic design and high specification of the building were to have a massive impact on the construction and would require a large amount of thought from Sheppard Robson as well as its appointed detailing architect, RHWL, and others involved in the project.
One of the most taxing construction issues that had to be confronted was the building’s huge glass facade. This feature was key to the architect’s vision to make No 1 stand out from its historical surroundings. Among the various problems was solar gain. A massive slab of glass such as this heats up the inside of a building, and could make life for its occupants uncomfortable.
The team’s solution draws upon the experience it has gained on other buildings, including the Helicon building in the City of London. There are two prongs to its approach, which transform the glass from being merely a very large window into a super-efficient triple-glazed “climate wall”.
One involves controlling the amount of light that enters the building through the glass by the use of louvers – similar to the slats of a Venetian blind – situated between the panes. These are linked to the computerised building management system.
The BMS is a complex piece of technology designed to improve the building’s efficiency. It is linked to external sensors that determine if the sun is out. It then automatically tilts the window louvers to an appropriate angle, minimizing solar gain for the time of day and time of year. The louver position is infinitely adjustable.
The shading of the climate wall by adjacent buildings has also been assessed. The louvers can remain open if the walls are in shade. The louvers can also be controlled manually, meaning the building has what Evans calls “both an active and passive facade”.
The alternative would have been traditional external louvers. But these can be costly to maintain and both birds and the microclimate can be a problem.
Graham Skinner, construction director for Allied London, says these issues have been avoided at No 1. “Internal adjustable blinds between the layers of glazing can be provided much more cost effectively in a climate wall than by the use of external shading, and the overall appearance of the building is better maintained,” he says.
The other important aspect to the climate wall is the capture of irradiated heat, which would otherwise have to be dealt with by the building’s cooling system. In this instance, hot air is captured within a 200mm-wide flue sandwiched between the two outer panes of glass and the single interior pane.
The cavity between the two skins is ventilated with “returned room air”, which is extracted from the interior of the building at the base of the glazing and returned back to the central air-handling unit via a duct at the top.
Says Skinner: “Since the cavity is ventilated with indoor air throughout the year, the inside surface temperature of the climate wall is close to room air temperature at all times, reducing downdraughts and the sensation of ‘cold radiation’ in winter, and reducing heat gains in summer.”
High specification
Although the climate wall is the building’s most impressive feature, the building’s specifications are high throughout, so its like has rarely been seen outside central London. It meets BCO best practice on issues such as optimum floorplate sizes, the availability of natural light and the suitability of materials and finishes. Sheppard Robson’s partner Mark Dillon confirms that BCO guidelines have been viewed as the minimum requirement in the construction.
Sustainability has also been taken seriously. Sheppard Robson has an in-house sustainability team which reviews all the buildings it is working on, and No1 went under its microscope. “The use of the triple-glazed facade and the overall choice of materials was informed by sustainability issues,” says Dillon.
The site is reclaimed, the basement is being reused and the high floor-to-ceiling height of 3m minimises the amount of artificial light required. All of this ticks the right boxes in terms of sustainability.
But with this high specification and the use of new technology haven’t a lot of things gone wrong? The short answer is no, because although, for example, the climate wall uses novel technology, its elements have been tried out in a limited number of buildings elsewhere, and the designers have picked up on problems that have arisen.
Cost of the climate wall
Another potentially troublesome matter is cost. Sheppard Robson will not say how much the climate wall cost but Evans admits that the capital investment needed for this building is “somewhat higher” than for a lower specification product. However, he counters this by saying that what is gained throughout the life of the building is “enormous”. “Where you need more sophisticated systems, obviously you need to spend more – but there are savings on running costs,” he claims.
As an example, if the internal window louvers were not in place, heavily tinted glass would need to be used. This would limit the amount of natural light that could enter the building, and increase the running costs for electric lighting. Similarly, if the flue within the glass void were not employed, more expensive mechanical air extraction would be needed elsewhere in the building.
Ingall’s view is that you get what you pay for. “It’s costing a lot of money but it will be the best building in Manchester. Both architecturally and in terms of specification, it matches anything in London,” he says.
No 1 Spinningfields Square is under construction and is expected to be completed next spring. Until then, work on the building can be followed via another hi-tech innovation. A webcam at www.spinningfields-manchester.com tracks progress and is updated regularly.
Tags: architecture, spinningfields
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