No. Landmark designation does not "freeze" a building or an area. Alterations, demolitions and new construction continue to take place, but the Commission must review the proposed changes and find them to be appropriate. This procedure helps ensure that the special qualities of the designated buildings are not compromised or destroyed. In addition, new construction may occur when an owner of a vacant lot wishes to construct a new building on the site. The Commission has approved such proposals when the design of the infill was appropriate to the character of the historic district. Such an example is the MOSS Bookstore at the corner of Second and Congress Streets.