Treble top

“Whatever you say about the roof, don’t say it looks like a Motorola flip top phone!” warns Peter Roberts, Bovis Lend Lease’s project director for the new arena taking shape in Liverpool.

If the connection is made, he advises, its designer, award-winning architect Chris Wilkinson, will not be happy.

The problem is, it does look like a flip top phone and, what with Wilkinson Eyre neglecting to return calls and present an alternative perspective, it’s not unreasonable to suggest so. Especially as the current aesthetic defining keynote buildings is one of mutable iconic forms that encourage the use of nicknames. Take the Gherkin in London, for example... sorry, that should be 30 St Mary’s Axe.

However, the building’s appearance is not an issue for Roberts, who is more concerned with logistics and deadlines than debates about form and mutability. Highly respected for his management nous – he picked up a silver medal in 2001’s Construction Manager of the Year Awards – Roberts was offered the project while managing the civil justice centre build in Manchester. A chance to build in his home city though – “a crackin’ place to work” – was a chance not to be missed.

The arena, which includes exhibition and conference space as well, is Liverpool City Council’s (LCC) flagship project, the largest on its books, and a vital part of the city’s bid to regenerate its once-much-busier docks.

It provides a link on Liverpool’s famous waterfront, plugging a gap between new office developments and the Albert Docks, with the Three Graces further afield.

A two-stage JCT 98 with novated design, work began on site last October, a month after Bovis had agreed a lump sum of around £120m with LCC. Progress has, necessarily, been speedy. Says Roberts: “It’s a tight programme. We’ve got a completion date set for January 2008 – to coincide with the ensuing City of Culture celebrations and we’ve got 100 daily deliveries to site and no room for storage. We’re spending a million pounds a week at the moment.”

But one element, the roof, causes no logistical or storage problems, because it’s delivered as a site-ready entity. Furthermore, subcontractor Prater has produced a plan that identifies every panel – a ProRoof system by Finnish firm Ruukki – and its installation position. Each one is numbered and loaded onto the wagon in the sequence it needs to come off. “Quite literally, a wagon backs up on site and a mobile tower crane takes it straight out the back of the wagon and lifts it into position. It never touches the ground,” says Roberts.

The building actually has three distinct roofs, one for each zone: the arena, the exhibition and conference centre, and an ETFE-covered, and consequently light-filled, public gallery space that links the two larger spaces. Identical from the outside, in section the arena roof differs from its conference-covering counterpart because it’s designed to deal with greater noise breakout. Hence it features two layers of the Ruukki panels, separated by a gap of just under a metre. Both roofs are topped off with the same waterproofing layer – a single ply membrane from Flagg, an Italian firm looking to grow its share of the UK market.

The new development has a low-slung profile and from a distance, appears to hug the ground, an effect partly achieved by digging down two metres. Roberts says this was a consequence of two requirements: a height restriction sanctioned by planning which didn’t want Liverpool’s world-famous skyline interrupted and a desire to bring visitors into the arena at mid-terrace level rather than on the performance floor.

By mid-September the arena roof steel was effectively complete, the conference steel about 60% done with roofing in the two major zones about a quarter of the way there. Roberts says it’ll be finished by the end of November with a new subcontractor starting ETFE installation just after Christmas. “You’ll be able to see the roof from a whole number of buildings around about,” he adds. “It’s very much been designed as a fifth elevation.”

Whether it, ahem, rings any bells with the Liverpool public, however, will be found out in 2008 when it opens.