1818 N Street is an eight story office building with two below grade garage levels located one block south of DuPont Circle.  Designed by David Schwarz Architectural Services, and constructed in 1984, this office complex incorporated five 19th century townhouses into its design.  Located within the DuPont Circle Historic District, the building project involved removing the interior structure of the historic townhouses while temporarily supporting their facades from the English basements to the gabled roof.  The original finishes of the existing facades were restored including ornamental masonry, windows and doors and cast iron stairways.  The office building is constructed behind this facade integrating the original townhouse floor elevations.  The building won the Masonry Institute Design Award.    In the 1890’s one of the original five townhouses located at 1812 N Street was home to Henry Martyn Robert, Brigadier General of the US Army.   Robert was the original author of the familiar manual of parliamentary procedures, ROBERT’S RULES OF ORDER.  In 2001, The National Association of Parliamentarians erected a marker at the building site in memory of Henry Martyn Robert.