The design of liverpool鈥檚 new arena successfully combines roof elements over three distinct areas.

鈥淲hatever you say about the roof, don鈥檛 say it looks like a Motorola flip top phone!鈥 warns Peter Roberts, Bovis Lend Lease鈥檚 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鈥檚 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鈥檚 Axe.

However, the building鈥檚 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 鈥 he picked up a silver medal in 2001鈥檚 Construction Manager of the Year Awards 鈥 Roberts was offered the project while managing the civil justice centre build in Manchester. A chance to build in his home city though 鈥 鈥渁 crackin鈥 place to work鈥 鈥 was a chance not to be missed.

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

It provides a link on Liverpool鈥檚 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 拢120m with LCC. Progress has, necessarily, been speedy. Says Roberts: 鈥淚t鈥檚 a tight programme. We鈥檝e got a completion date set for January 2008 鈥 to coincide with the ensuing City of Culture celebrations and we鈥檝e got 100 daily deliveries to site and no room for storage. We鈥檙e spending a million pounds a week at the moment.鈥

But one element, the roof, causes no logistical or storage problems, because it鈥檚 delivered as a site-ready entity. Furthermore, subcontractor Prater has produced a plan that identifies every panel 鈥 a ProRoof system by Finnish firm Ruukki 鈥 and its installation position. Each one is numbered and loaded onto the wagon in the sequence it needs to come off. 鈥淨uite 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,鈥 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鈥檚 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 鈥 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鈥檛 want Liverpool鈥檚 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鈥檒l be finished by the end of November with a new subcontractor starting ETFE installation just after Christmas. 鈥淵ou鈥檒l be able to see the roof from a whole number of buildings around about,鈥 he adds. 鈥淚t鈥檚 very much been designed as a fifth elevation.鈥

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

Arena zone(left section of building)
Ruukki鈥檚 ProRoof system, topped off with single ply membrane from Flagg, was chosen for the large event spaces. In the arena, main roof trusses span east-west but there鈥檚 also a secondary truss layout sitting on top of that running north to south, to allow for the placement of two layers of the Ruukki system 鈥 on the top and bottom faces of the secondary trusses. Says Roberts: 鈥淭he panels are quite literally laid in place and bolted down 鈥 there鈥檚 no elaborate fixing details. That鈥檚 why it鈥檚 so successful; ease of installation and speed.鈥


Atrium corridor
The 鈥済alleria鈥 is essentially a wide corridor that links the two event spaces. Its roof construction features an expressive steel frame accommodating ETFE 鈥渃ushions鈥, that will allow daylight to penetrate the space. Its detailed design and installation is being handled by Vector Foiltec, which invented the technology in the 鈥80s. Called Texlon, the system comprises a number of layers of the UV-stable copolymer ethylene tetra fluoro ethylene (ETFE) that are welded into cushions or foils.


Exhibition and conference zone(right section of building)
The conference and exhibition space, with less noise breakout, requires only one layer of the Ruukki system, and it sits on top of the main truss layout. The first truss, spanning over 90m, was placed into position in June. Carried out by Watson Steel Structures using crawler cranes, by September steelwork for the roof was nearing completion. Trusses arrive in pieces, are built on site, go up in two halves and are locked together using a pin and plate arrangement.

Safety conscious

Project director Peter Roberts says Bovis stands apart from other contractors by involving the HSE with packages due to begin on site.


鈥淲e insist subcontractors make a presentation to us and then to the HSE of how they intend to go about their works,鈥 he explains. 鈥淭he HSE then have the opportunity to comment on that. To the best of our knowledge, nobody else does this.鈥


And if the HSE recommends a change, Bovis makes sure it鈥檚 carried out.