Owners of dwellings and structures of a mixed residential and commercial use rehabilitated under this section shall, during the period of five years following the completion of such rehabilitation and in any event during the period any mortgage loan made under this section to finance such rehabilitation is outstanding, and subject to such regulations as the department may establish, give preference in the selection of tenants for such dwellings, first to the individuals or families in occupancy thereof last prior to such rehabilitation and second to other residents of the city or town in which such dwellings are located; and who are able to pay rents charged other individuals or families for similar or comparable dwellings in the urban renewal project area.