The Washington state Department of Corrections says it expects to award a $26.8 million construction contract to Spokane-based Lydig Construction Inc.

The project will include constructing two housing structures and a kitchen expansion at the Washington State Penitentiary, in Walla Walla, says Nanette Graham, project manager for the department.

Construction is scheduled to begin early next month and to be completed in the spring of 2013, Graham says.

The two-story housing structures will be intended for medium-security inmates, and each will have 256 beds and 47,500 square feet of living space, she says. The building addition will add 3,500 square feet of floor space to the 13,000-square-foot kitchen in the prison's west complex.

Lydig is the apparent low bidder on the project, which was bid on by three other contractors, including Garco Construction Inc., of Spokane.

KMB Design Groups Inc., of Olympia, designed the project.

The prison, about 160 miles southwest of Spokane, houses about 2,200 inmates.

Lydig is experienced in constructing prison facilities. The Department of Corrections awarded the company a $23 million contract in 2008 to build a 49,000-square-foot medical structure at the penitentiary. Lydig completed it last year.

Lydig also teamed up in 2009 with Hunt Construction Group, of Phoenix, in a joint venture to build the $160.5 million, 1,782-bed Coyote Ridge medium-security prison expansion at Connell, Wash.