A proposal to transform a parking lot next to Portland Maine City Hall into a complex of condos, shops and a 156-room hotel has been approved by city officials. Herald Square, would occupy a 2.26 acre parcel at 385 Congress St., bounded by Cumberland Avenue, Myrtle Street and Pearl Street. City Hall and Merrill Auditorium sit immediately across Myrtle Street. A 12-story hotel is the first of four building that would ultimately create three interconnected buildings and 667,000 square feet of residential and commercial space. The project is proposed by developer Joe Dasco, of Reger Dasco Properties and would also include 297 condominium units, 11,600 square feet of retail space, a 5,100-square-foot restaurant and 337 parking spaces in an underground garage. There would also be a 19,000-square-foot amenity deck a second-story, open-air promenade accessible to the public. Construction costs are estimated at between $200 million and $300 million. CBT Architects is designing the project.