GREENBRAE -- Marin General Hospital will have two more years to seismically retrofit the aging campus, following the approval of an assembly bill Sunday. Without the adjustment, the hospital would have had to be completely rebuilt by 2013.

Assembly Bill 523, authored by Assemblyman Jared Huffman, D-San Rafael, applies specifically to Marin General and was signed into law Oct. 11. The legislation is effective immediately. In a release sent by the Marin Healthcare District late Monday, officials said construction will begin in January 2012 and conclude in 2015.

“Because of our unique circumstances here in Marin, it appears the Marin Healthcare District is the first to have received one of these special extensions, and we greatly appreciate it. This will allow us the time needed to really design and build the hospital Marin needs now, and deserves well into the future,” said health care district Chief Executive Officer Lee Domanico.

Analyses of the bill say the need is based on the unique constraints concerning the pending transfer of management. Sutter Health is currently leading the hospital, but the district will officially assume the role next June.

To meet state earthquake safety standards, a majority of the hospital will have to be replaced, which officials calculate will cost as much as $400 million.