MINNEAPOLIS — Some clues are emerging about the design of the new home for the Minnesota Vikings.

The stadium will be taller and bigger than the Metrodome and will have a sloped roof. It might feature a retractable roof or retractable walls that open to the downtown Minneapolis skyline. It also might bear some resemblance to the Beijing National Aquatics Center, commonly known as the Water Cube, from the 2008 Summer Olympics.

Those details are contained in a nearly 400-page draft environmental impact statement released Monday by the Minnesota Sports Facilities Authority.

Chairwoman Michele Kelm-Helgen says the new document contains a lot of options and cautions against speculating which features are in or out of the design.

The authority plans to unveil the preliminary design for the $975 million stadium May 13.