Invest DSM is accepting proposals for the redevelopment of vacant property at 3524 Sixth Ave. in Des Moines. The site had been home to the Highland Park Apartment Building, which was recently torn down. Invest DSM, a joint effort between the city of Des Moines and Polk County to expand revitalization efforts in the city’s neighborhoods, owns the property. The nonprofit group has proposed developing a mixed-use project on the site called Commons at Highland Park. Proposals are due by 5 p.m. Nov. 30. For more information about the request for proposals, click here. Developers interested in learning more about the project are invited to attend an information meeting from 8:30 to 10 a.m. Thursday at Invest DSM’s offices, 525 S.W. Fifth St., Suite F, in Des Moines.