Once the Georgetown estate of Robert and Mildred Bliss, Dumbarton Oaks is now a research institute and museum of Byzantine studies owned by Harvard University. The historic Orangery is located on the east side of the original Bliss mansion and continues to serve as a winter citrus greenhouse as well as a summer gathering and events venue. The Orangery lacked an accessible restroom and adequate support space required for catering. cox graae + spack architects designed a sensitive addition to the historic structure providing much needed support for museum lectures and social functions. Additionally, the Orangery’s failing existing skylight was replaced to accurately replicate Architect McKim, Meade and White’s historic glass greenhouse roof utilizing contemporary materials and technology.