The Glebe House stands on a parcel of property that was originally part of a tract of 516 acres purchased in 1770 for the Glebe of Fairfax Parish. Fires 1808 and 1840 destroyed early structures on the site. In 1855, the distinctive octagonal main house was constructed to reflect the “rage” in residential architecture at the time. Through the years, numerous families, prominent in local and state history, have owned the Glebe House and it has remained relatively un-altered. The house was listed on the Virginia Historical Landmark Register in 1971 and on the National Register of Historic Places in 1972. The Ortman family purchased the house from the National Geological Society in 2004 and commissioned cox graae + spack architects to design modifications to accommodate their growing family. Alterations of the original historic residence include removal of a non-contributing addition, preservation of the historic fabric and restoration of original architectural details. An addition, designed in accordance with the Secretary of the Interior guidelines sympathetically expands the house’s usable area. All design efforts were coordinated with and approved by the Virginia State Historic Preservation Office and the local Historic Affairs and Landmark Review Board.