A key vote is expected this week on the proposed headquarters for the Unites States Institute of Peace, an iconic steel-and-glass structure slated for a high-profile intersection adjacent to the National Mall.

The $175 million project, pegged for a 2.5-acre U.S. Navy parking lot at 23rd Street and Constitution Avenue NW, has been in the planning stages for more than a decade. The National Capital Planning Commission is expected on Thursday to approve the conceptual design, one of the last required steps before construction can begin.