Designing an icon is difficult enough. But the task facing the shortlisted architects in filling the 'Fourth Grace'site in Liverpool is even more onerous: the design of an icon which is, at least partly, self-funding.
Designs by Alsop Architects, Edward Cullinan Architects, Foster and Partners and Richard Rogers Partnership went on display at the city's Walker Art Gallery this week (until 17 November), before judging later in the month.The judging is not going to be easy: each scheme is different - in content, mix and size - and requires a different level of public subsidy.
The competition, launched at the MIPIM exhibition in Cannes in the spring, is organised by Liverpool Vision - the city's regeneration company - and other partners including the North West Economic Development Agency. Rather than seeking an 'icon'pure and simple, competitors were asked to assemble consortia including developers, and to make financial proposals as well as designs. In other words, the simplicity of an ideas competition was rejected in favour of a 'real' exercise.
The architects have responded accordingly, larding their proposals with (most obviously) housing, plus some office, retail, hotel and other uses. But in each case, the fixed requirement for a museum space has been acknowledged, though it is not entirely clear what the final content of the museum will be. Current plans for it to be devoted to Liverpool life would mean shutting an existing museum next door.
In this competition, however, it is not so much the uses which matter as the visual impact of the proposals. Form will follow a function which includes skyline impact. The sponsors want a show-stopper. This creates a dilemma for the architects. Do they make the housing towers the visual focus, or the 'cultural'building?
That is not the end of the problem. Designs have to incorporate the possibility of an extension of the Manchester-Liverpool Canal in front of the Three Graces, connecting to the South Dock. There is then the connection to the hinterland, particularly the Strand, the wide road which cuts off the waterfront from the centre of the city.
And, finally, there is the relationship to the existing Liver, Cunard and Port of Liverpool buildings, commercial space built in an era of selfconfidence in which public money was certainly not a requirement. A tall order indeed.