Detroit's Cobo Center through the years Cobo Conference and Exhibition Center has dominated the heart of downtown Detroit since it opened in 1960. It was built by the city of Detroit and named in honor of former Detroit Mayor Albert Cobo (1950-1957). It is shown here May 20, 1962. The Detroit News archives
Remediation costs vary depending on how much and where mold exists. Figure on: 1  $500 to $4,000 to remove mold from crawlspaces only.  $2,000 to $6,000 to remove mold from ducts, crawl spaces, walls, and attics.
Average Costs. In general, remodeling an attic into a bedroom can cost between $40,000 and $90,000. According to Hanley Wood, a real estate media company, the 2008-2009 national average cost to build an attic bedroom in the U.S. was $48,393.anley Wood reported that the average U.S. attic bedroom remodeling in 2008 and 2009 achieved a resale value of $35,694, about 74 percent of the $48,398 project cost.