Spec development making a comeback.

Speculative office development is starting to reappear in a few downtown areas.

Designer/builder/developer Opus Northwest L.L.C. plans to begin construction soon of a 30-story, 700,000-sq.-ft. office building that will be the first speculative office development in the Minneapolis central business district since four major projects were completed in 1991.

Opus, which has secured financing for the $105 million project, said a strong interest from prospective tenants prompted its decision to proceed. "We continued to become more bullish on the downtown Min