Ironbank, Samson Corporation's revolutionary new Auckland building, was runner-up in a European architecture award.

The building, designed by RTA Studio, made it to the shortlist of the World Architecture Festival, which drew hundreds of entries, and was highly commended.

The winning office building was Unileverhaus by Behnisch Architekten, Germany.

Ironbank, the office and retail building at 150-154 Karangahape Rd, is in the block between the top end of Queen St and Mercury Lane.

Marco Creemers of Samson said the commendation was a big boost.

"Technically it means we have the second best office building in the world, which Ironbank tenants will experience first-hand. In light of the current recession, we have strong leasing inquiry with 30 per cent of the retail space leased and final negations taking place for more than 20 per cent of the office space," he said yesterday.

Judges praised the building for how it relates to the urban landscape.

"The Ironbank office project created an intricate public route through a city block surrounded by densely packed, small start-up office spaces. Its sophisticated attitude to the messy urbanity of south-central Auckland made a real impression on the jury," the citation said.

Four other New Zealand architecture practices made the shortlist: Warren & Mahoney for the Nzi3 building at Canterbury University, Pacific Environments Architects NZ for its Yellow Treehouse Restaurant at Pohuehue north of Auckland, Opus Architecture for the new Wilson School at Takapuna and Fearon Hay for the Northern Club extension in Auckland.

The festival was held in Barcelona from November 4 to 6.

RTA got a highly commended award in the office category, competing against big-budget European and Asian projects.

John Walsh, editor of Architecture New Zealand, said RTA Studio did well to not only make it to the shortlist but to also be highly commended.

"It's a very tough competition against very sophisticated architecture practices around the world.

"You have to defend your project in front of a very informed judging panel so it's a great opportunity for New Zealand architects to showcase their work. It's a real achievement to get there in the first place and shows our architects are doing some fine work here.

"It's a big investment to travel all that way and all the five firms from New Zealand were represented."

New Zealanders made the shortlist last year but none were highly commended or won category awards, said Walsh, who was a judge on a panel last year.

He judged cultural buildings and the winner was the Oslo Opera House, by a Norwegian practice.

"This is the best anyone from New Zealand has done in this award," he said.

Last month, the 4500sq m Ironbank building won RTA Studio an Institute of Architects' Auckland area prize.

The building has robots stacking cars on a four-level wall, sophisticated environmental features and no air-conditioning.