The patrons of the new museum intend to keep the original facade of the Randall School in Southeast D.C. which was built in the "early 20th Century."(1)(2) Preliminary plans show that within this facade there will be dramatically modern architecture, although the firm Bing Thom Architects is still in the development phase.(3) This composition of modern within old style closely compares to an example of postmodern architecture, the Harold Washington Library in Chicago.
Many art museums hired the premier modernist architects of their time to design their buildings, to illustrate how in-touch they were with the prevalent architectural style and to give their endorsement to its intellectual concerns. (Or museums chose to move into already existing modernist buildings, showing that they considered it the appropriate setting for their art collection.) Examples of this include the Kreeger Museum in Washington D.C. designed by Phillip Johnson in 1974 and the National Museum of Western Art in Tokyo designed by Le Corbusier in 1959. Similarly the most important modernist architect to work in America, Mies van der Rohe, designed one of the buildings of Houston's Museum of Fine Arts.
National Museum of Western Art, Tokyo, 1959, Le Corbusier
Though "modernist" architecture is a broad term applied to many different architects with different outlooks, post-modern architecture can be (very simply) distinguished from it in that the latter makes use of references to earlier architectural styles as well as ornamentation. The pioneer of postmodern architecture, Robert Venturi, summed this up when he transformed Mies van der Rohe's saying "less is more," into "less is bore."
An example of postmodern architecture which serves as a good comparison to what the Rubell D.C. museum may look like is the Harold Washington Library in Chicago, designed in 1987 by the firm Hammond, Beeby and Babka. This building features a facade that intentionally imitates a facade from the late 19th or early 20th century. Behind this facade the building takes on a minimalist style that is similar to the modernist work of Mies van der Rohe, such as his IBM plaza building.
Harold Washington Library, Chicago, 1987-1991, Hammond, Beeby and Babka
Though the Rubell Contemporary Art Museum in D.C. is still in the development phase, the decision to keep the old facade along with the preliminary plans which use very "modern" architecture means that it will fit in with the conception of postmodern architecture. The Rubells are prominent international art collectors known for their support of the avant-garde of contemporary art. For them to go forward with a design featuring an old facade and a new interior at the very least indicates an acceptance of the use of reference, which was controversial when postmodern architects reintroduced it.(4) At the other extreme, it could be considered a full-on endorsement of postmodern architecture by the new contemporary art establishment, a big shift away from the dominance within the art-world that modernist architecture once enjoyed.
(4) The use of references to past styles in contemporary architecture has been attacked by some on the grounds that those past styles used form which was designed for their specific time, and that contemporary architecture should use a 'contemporary form' that speaks to the contemporary human.