The Walkie Talkie’s ‘death ray’ effect that melted a Jaguar car parked on the street below should have been identified during early stages of design, experts have claimed.
The £500m 37-storey skyscraper, now dubbed the Walkie Scorchie, is being built at 20 Fenchurch Street in London. It features a 33,000 sq m south-facing concave glass facade, which reflected a dazzling beam of sunlight that blinded passers-by and caused damage to several vehicles. The problem has forced joint developers Land Securities and Canary Wharf to take urgent action to “cover up” the problem.
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But façade engineers commenting on a Chartered Institution of Building Services Engineers (CIBSE) discussion forum on the subject claim the issue could have been avoided entirely if solar reflection had been analysed properly during design.
“It seems almost inconceivable that this wouldn’t have been checked during design,” said one engineer. “Given the high profile of this I can see solar reflection tests/modelling becoming a requirement, if not UK wide then at least for London based developments.”
“We need to rethink solar heat gain mitigation strategies that indiscriminately dump our building problems onto others – that can’t be sustainable?”
CIBSE member
A director at a major engineering consultant added: “You’d like to think that if a problem has already been found with one building by the same architect [Uruguay’s Rafael Viñoly] steps would be taken to ensure it is not repeated,” referring to an incident at the Vdara Hotel in Las Vegas in 2010, where guests were badly burned by sunlight reflected from the building’s curved facade, which also melted disposable drinks glasses and other objects.
“These issues could have been prevented if the models were developed in the early stages,” said another building services engineer, who cites the Vdara case alongside evidence of solar reflection issues on several flat-sided buildings. “The lawyers are going to have a wonderful time – it’s hard to argue against this sort of evidence. We need to rethink solar heat gain mitigation strategies that indiscriminately dump our building problems onto others – that can’t be sustainable?”
The Walkie Talkie is due to be completed in 2014 and is designed so that its floor plates widen at the top of building to create enough space on the roof for a publicly-accessible garden observation deck.
In a joint statement, Land Securities and Canary Wharf said the problem, which resulted in temperatures approaching 70oC, was caused by “the current elevation of the sun in the sky, which currently lasts for approximately two hours per day, with initial modelling suggesting that it will be present for approximately two to three weeks”.
On Wednesday, the developers said they would erect a temporary scaffold screen at street level on Eastcheap designed to minimise the impact on the local area over the next two to three weeks when the sun is at its hottest.
Meanwhile, reports are suggesting that fixing the problem could cost millions of pounds. Potential long-term solutions could include treating the glass, applying an external film, adding external shading elements, or replacing one or more of the facades. The estimated costs of the solutions range from £60,000 to several million pounds, reported Building magazine.
