The plan also calls for turning the Smithsonian Castle, dating from 1855, to the centerpiece of a visit to the grounds. The largely administrational building will be opened up inside, allowing for new spaces for services and other amenities. Making additional space from current buildings is central to the entire design — most all of the structures would be modified under the plans to make additional space for galleries, bringing the exhibition spaces up-to-date for modern shows.
Unfortunately, you shouldn't expect to see any of these changes during your next visit to D.C. The plans, which have been in the works for a year and a half, don't include a solid timeline or funding. The Smithsonian expects to use a mixture of public and private funding to raise the $2 billion needed for the project, and even then the renovations won't be complete for 15 to 20 years.