London, United Kingdom -Assemble, the architectural collective shortlisted for this year's Turner Prize, reckon their nomination has launched a fresh debate about the state of contemporary art in Britain.

The London-based group has blurred traditional boundaries between art and design with its redevelopment plans for 10 Victorian houses in the run-down Toxteth district of Liverpool, northwest England.

That project, along with a children's adventure playground in the Scottish city of Glasgow, earned the group its place among the four finalists shortlisted in May for Britain's top contemporary arts prize.

"It was a massive surprise," said Joe Halligan, standing outside the former factory which serves as their studio in the Olympic Park in Stratford, east London, clad in khaki work clothes.

"As a nomination, it is like starting a debate about art and the place that art is in at the moment.

"We are not allowed to call ourselves architects because none of us is fully qualified and before we got nominated for the Turner Prize, I don't think anyone would have called us artists," he explained.

Fran Edgerley, one of his colleagues, added: "That was just crazy... We never really thought ourselves to be in that world, the art world."

The Turner Prize is known for its surprising choices. Awarded in December, it has been handed out every year since 1984 to an artist aged under 50 who is living in, or was born in, Britain.

It is closely followed as a marker for art world trends, but is also frequently mocked by critics of the contemporary art scene.

Never before had a group so large -- 18 founder members of whom 14 are active, all in their 20s -- been nominated, even more surprising given that they are rooted in architecture.

- 'Something real' - 

The group started as friends at the prestigious University of Cambridge, where many of them studied architecture while others came from different disciplines, but all shared the "idea to do something real in the city," said Edgerley.

She said they felt "dissatisfied by the disconnect between their interests and the reality of making cities -- and the fact that you spend a lot of time on a computer drawing stuff that never gets built."

Their first project, completed in 2010 during their weekends and holidays, was transforming a former central London petrol station into a temporary cinema, called the Cineroleum.

Nothing was formalised at this stage, but their methodology was firmly established: cheap or reclaimed materials, a Do-It-Yourself approach and close collaboration with the public.

With no money around, Edgerley said the group did their early projects for their own amusement.

"It was really enjoyable. That was actually part of the project: everyone learning how things work," she said.

The Cineroleum has gone but some 20-odd projects later, the philosophy and approach remains the same.

Assemble have set up a building so local youngsters themselves can make fittings that will adorn the homes they are working on, including chimneys and door handles.

"We've tried to do the (Liverpool) houses in the same way that someone would do it themselves," said Halligan.

Likewise, at another project under way on a public housing estate in east London, Assemble members are working side-by-side with the inhabitants to create a garden in the heart of the complex.

Four years after its official launch, Assemble is still grappling with the need to install some formal structure without losing the spontaneity of its origins.

There are 14 active members -- eight men and six women -- said Edgerley, "but it's quite fluid".

"Some people want better job security and other people prefer to do other things with their time," she said.

Each one chooses whether to work on a project or not. Every Monday evening, members meet, voice their views and vote on big decisions affecting the group.

"There's no hierarchy; everyone is on the same level," said Edgerley, adding that the collective's informality is "the main quality that we are trying to protect".

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