Neumann Homes, a production home builder active in the Chicago, Denver and Detroit markets, has closed its offices and laid off most of its workers, according to various news reports. In a prepared statement, CEO Kenneth Neumann announced that the downturn in the housing market has forced the Chicago-based firm to cease operations and prepare to file for Chapter 11 bankruptcy protection.

In particular, Neumann cited losses of $60 million in the Detroit market, which the company entered in 2005 with an acquisition.

Founded in 1985, Neumann is the 35th largest home builder in the United States, with revenue of $518 million in 2005, according to Hoover’s Company Records.