Try searching for your specific building and for related concepts such as the architect, style, or region of your building.
General terms:
Architecture -- Washington (D.C.)
Washington (D.C.) -- Buildings, structures, etc.
Architectural style/type terms:
Architecture, Classical
Architecture, Modern
Art deco (Architecture)
Brutalism (Architecture)
Specific buildings and architects:
Hirshhorn Museum and Sculpture Garden
Glenstone (Museum)
Latrobe, Benjamin Henry
Pei, I. M.