US Botanic Garden Conservatory Facade Restoration and Vegetative Roof Integration

The US Botanic Garden, located within the District’s monumental core, contains a Beaux-Arts-style conservatory, which was completed in 1933 and remains a popular visitor destination throughout the year.

KCCT was selected by the Architect of the Capitol to prepare an existing conditions survey and evaluation report of the stone facade of the conservatory. Based on the findings, KCCT provided construction documents to correct the damage. As a result of critical findings reported during the survey, the Architect of the Capitol also contracted KCCT to repair the building envelope. The aging roof was replaced with a vegetative roof assembly funded by the University of Maryland and designated for research and educational purposes.

The project consisted of three interrelated tasks:

  • Restoration and cleaning of the limestone facade, which had developed a repetitive pattern of vertical cracking and spalling from the base of the building to the cornice
  • Protection of the vulnerable parts of the headhouse from seismic activity
  • Reroofing of the headhouse to correct water penetration into the building and exterior stone walls, as well as to implement sustainable water energy and conservation practices

After restoring the damaged portions of the masonry facade, the design secured the building’s envelope to restrict destructive moisture from penetrating it. KCCT developed a method to protect the structure from seismic events by dismantling and rebuilding the parapet with adequate reinforcement and new wall flashing.

KCCT established a phasing plan that allowed the US Botanic Garden to remain open to visitors and fully operational throughout the restoration effort. Through this project, the Architect of the Capitol was able to align its vision for a sustainable future while still preserving the Botanic Garden’s rich architectural legacy.



Washington, DC


28,944 SF


Architect of the Capitol


• Architecture
• Historic Preservation
• Construction Administration