Wilford was allowed to do pretty much whatever he wanted here. The site, a peninsula jutting into enormous sheets of deserted water, was a flattened wasteland. Earlier regeneration on the quays had taken the form of banal office blocks, hotels and housing. The client - at first Salford City Council, later an independent trust - badly wanted a landmark as well as a cultural magnet. Local planners were never going to dig in their heels over how it looked. This is a horizontal land and waterscape dominated by a few very large objects - a giant flour mill, the enormous Old Trafford football stadium. The Lowry responds to this setting in Wilford's typically vigorous way. In a couple of years it will be joined by the no less assertive forms of Daniel Libeskind's £28.5m Imperial War Museum of the North, facing it from the Manchester bank of the ship canal. These are buildings that - far from hunkering down in some sensitive cityscape - have to shout and wave in order to be noticed at all.

The Lowry is one of very few of our big new cultural buildings to be genuinely new - not a conversion or extension. London, where grand conversions are the order of the day for Lottery projects, has nothing like it. At first glance, with all those jostling shapes, it might seem confusing. But it has a very simple layout indeed. The site is roughly triangular, therefore so is the building - an echo, perhaps, of Stirling and Wilford's other famously controversial triangular building, known only as "Number One Poultry" after its medieval street in the city of London, an office and shopping block over which planning wars raged for a decade. But there the resemblance decisively ends. There is a cylindrical tower and giant canopy at one end, a low glazed drum at the other, flanks like big rectangular fish-tanks, the unmistakeable tilted wedge of a theatre auditorium and square stump of a flytower rising in the middle. In fact there are two theatres - one large 1730-seater, which is blue/purple inside, and one small adaptable red/orange one. These sit back-to back, with the smaller one towards the narrow point of the building beneath the rotunda. The two rectangular wings of the art galleries - one for Salford's Lowry collection and temporary shows, the other for interactive art of some description - sit on either side, in V-formation. The space between the theatres and the art galleries forms a lavish enclosed public concourse, running right round the building. It feels like the 'ambulatory' of a medieval cathedral, with the theatres standing in for the chancel, and the art galleries for the side chapels.