Officials for the state agency handling the Opera House's construction, Statsbygg, started noticing several months ago that newly laid marble was turning yellow both inside and outside the building.
Project leader Erling ES Magnusson is one disappointed man. "Nobody wants this, we don't like it, and I'm very unhappy about it," he told Aftenposten over the weekend.
The yellowing is a mystery for all involved, with neither the Opera House's architect, its builders or the supplier of the marble in Italy able to explain why it's already losing its snow-white colour and developing ugly streaks of yellow.
Some experts tried to attribute the yellowing to the exhaust and other air pollution coming from the motorway that runs alongside the Opera House's waterfront location. The motorway is soon to be torn down and replaced with an undersea tunnel.
But that doesn't explain why the marble is also yellowing inside the Opera House, where it's not subject to air pollution or climactic factors.
"We don't know why it's yellowing," Magnusson said. "It may be a reaction between the elements in the marble, oxygen and moisture."
Use of the marble, which comes from Carrara in Italy, was controversial, with some politicians arguing in favour of using Norwegian granite instead at twice the price. But Snøhetta, the architectural firm that won the job, insisted on the marble, and still claims it was the right choice. The marble, says Snøhetta, was tested in a laboratory and approved by research organization SINTEF.
Others contend marble isn't suitable in Norway's frosty climate, because it can absorb moisture.
Heidi Grande Røys, the government minister in charge of such major construction projects, has ordered a full report on the problem from Statsbygg. "We have to find out why this is happening and what we can do to solve the problem," she told Aftenposten. Minister of Culture Trond Giske says he's worried as well.
The Opera House, meant to be a glistening new landmark on Oslo's harbour, is due to open in mid April.
