Birmingham's £6bn makeover

Britain's new architectural hot spot is Birmingham and it's handing £6bn to a thundering horde of architects to prove it. First up, in a £193m scheme, Europe's biggest library, care of the acclaimed Dutch designers Mecanoo. And even the sky isn't the limit for Birmingham's architectural ambitions. The mere ether above the Bullring is not good enough for Brum's director of planning, Clive Dutton: "We're going to illuminate Spaghetti Junction – you'll be able to see it from space!"

Suborbitally, 25 floors up in the Alpha Tower overlooking the modern urban landscape of the 19th century's "workshop of the world", Dutton is riffing on the huge architect-led schemes that will set Britain's self-proclaimed Second World City apart – and particularly from London, whose inhabitants traduce Birmingham as a metropolis that hasn't got over being described as a village called Bremeingaham valued at 20 shillings in the Domesday Book.

Dutton is, charmingly and irrefutably, a can-do beatbox with extraordinary figures and visions of the future: a £2.4bn makeover of all 89 secondary schools in Birmingham, by a multi-practice team led by British architecture's latest spotlight kid, Deborah Saunt; New Street Station's £620m refurbishment by bendy-thingers Foreign Office Architects; a new £81m magistrates' court by the hip Australian practice Denton Corker Marshall; the V Building tower by Eric Kuhne Civic Arts, those wonderful folks who gave us Bluewater; the Cube mixed-use building by Ken "The Pen" Shuttleworth's practice, Make; and the £400m Arena Central development, designed by HOK. Schemes such as these are expected to create a wildfire of private investment, boosting the city's £6bn regeneration stake with a further £11bn.

And these are only the headline projects: more than 20 others are either on site, or in design phases. Dutton declares: "We want 10 of the world's best architects to work in Birmingham. We're talked about as Britain's second city. We don't like that. We're a world city. A lot of cities have their shtick – Liverpool, City of Culture, Manchester's got the brand of its football club. In Birmingham, it's regeneration.

"Birmingham's the equivalent of a FTSE-100 company, with a £3.5bn annual budget. We think we know what's best for Birmingham. Our Big City Plan isn't a planner's plan. It's a never-ending plan, spawning ideas and themes through public consultation, the like of which has never been seen before." And the beat goes on: "The Big City Plan is economic cycle-proofed... Bonded development... We're going to give Birmingham a river... We'll create three new towns in the inner city... It's long overdue, it's profound."

Dutton says long-term regeneration depends on Birmingham being "re-imaged" with world-class architecture. It's telling that the city council's list of "notable developments" mentions only five projects: the Rotunda, a cylindrical 1960s high-rise shazammed into apartments by Urban Splash; the £35m refurbishment of the Town Hall; the Millennium Point science and education centre; the Mailbox mixed-use development; and the supersized sequinned girdle known as Selfridges. Of these, only the rough, radiant marble of the Romanesque 1834 Town Hall can be safely described as an architectural delight.

Dutton insists that Mecanoo's library and Rep theatre complex "will be the most important public building in Birmingham for a century". Just as Richard Rogers' earlier library scheme was supposed to be, before it was dropped.

A day after meeting Dutton, I'm in Mecanoo's Delft office, running my fingers over a model of the new library. Am I touching something that will "re-image" Birmingham? Mecanoo were key players in the mid-1990s SuperDutch architectural movement, whose mixture of pragmatism, spatial clarity, and graphic and formal asymmetry has informed projects all over the world.

"We want the library to surprise and excite," says Mecanoo's founder and principal, Francine Houben. "When I looked in a tourist guide for Birmingham, there were only two pages, and the only image is Selfridges. I told them they needed coherence. I felt instinctively what we needed to do – not to fly in and say, here's a big architectural icon by Francine or Mecanoo. I wanted it to be a philosophy of the city and and a philosophy of adventure inside the building."

The library's design is essentially about circles and tubes, reflecting two conceptual thrusts: the library as a 21st-century palazzo forming part of a new pedestrian scenography along a key city-centre axis; and the imagery of gasometers, rotundas, and Brum as "the cast-iron city". The library will, in effect, be five massive concrete cylinders stacked asymmetrically, boxed in glass, then sheathed with screens of steel circles which refer to 19th-century craftsmanship in a universal pattern that creates "beautiful shadows".

Externally, the architecture will seem massive and ornate. Inside, Houben's quest for "a dynamic journey of discovery" will probably be fulfilled – the rising asymmetries of the core spaces will see to that. There will be two gardens set into the upper edges of the building, overlooking the city, and she has rightly identified the need to activate the uncannily dreary Centennial Square in front of the library. Here, a big circular hole will be punched down through its surface to a sunken patio with a pond and single tree that will be part of the library's subsurface level. At the top of the building, the city's magnificent Shakespeare archive will float over Prospero's island in the West Midlands. But will it draw as many visitors as Hopkins Architects' Forum, otherwise known as Britain's most visited library?

And is Birmingham over-existing, architecturally? This is a city that contains more than a million people, with a greater metropolitan area of 2.3 million citizens. But its physical coherence has been fractured by the post-war city planning of Sir Herbert Manzoni, and by infrastructure that has produced a collage of urban briquettes. Will big bangs such as the library work for, or against, urban complexity and change?

The library is a hugely important cultural scheme – "a people's palace in a city of many incidents and identities," as Francine Houben puts it. Yet there is surely greater strategic importance in what Dutton says about the more general development of the inner city "with Birmingham neighbourhoods, Birmingham streets, Birmingham buildings". By that, he means very different kinds of buildings, cheek by jowl, a new kind of mixed commercial and domestic milieu featuring fresh approaches to high-density architecture; and at Longbridge, a £750m development will create 1,450 new homes.

These schemes will require design skills of a very different order to those which produce "headline" buildings. Mecanoo will again be involved, no doubt. But if the admirable Clive Dutton is going to be really ambitious about creating a Birmingham that re-energises its "many identities", he will also turn to acutely talented new-wave architects such as Patrick Lynch, Stephen Taylor, Dow Jones, Grafton Architects, and De Metz Forbes Knight – all of whom are capable of lucidly creative, rigorously critical takes on context, history and daily life that don't have to impress astronauts, orbiting Birmingham from outer space.