LONDON—The Tate Modern has announced that plans for the new wing have been revised by architects Herzog & de Meuron and that the planned 2012 opening of the new space may be delayed due to tough fund-raising conditions, reports Bloomberg. 

Tate director Nicholas Serota and architect Jacques Herzog said that the new building, originally conceived as a jagged cast-glass pile, will now be a brick polygon that extends from the existing building. They denied that budget problems occasioned the redesign, which maintains the project's original £215 million ($429 million) cost, at 2012 prices.

"It's not cheaper," Herzog said. "It's really to make everything better: more efficient, more compact, more flexible, and more green."

The new plans will allow Tate Modern to be more environmentally friendly by using 40 percent less energy and generating 35 percent less carbon. 

Serota said that the new plan is slated for completion by the time of the 2012 Olympics in London, but added that the opening could be postponed to 2013 or 2014, depending on fund-raising progress. He described the current condition as "probably the most challenging time to raise money in the last 25 years." So far, Tate has received £50 million from the government, £7 million from the London Development Agency, and £13 million from private donors.