Washington, DC

Dumbarton Oaks


Dumbarton Oaks Research Library and Collection, a Harvard University institute, supports Byzantine, Pre-Columbian, and Garden and Landscape studies. Originally housed in the 1801 home purchased by Mildred and Robert Woods Bliss, the institute now includes expansive gardens and numerous buildings. As part of a rehabilitation effort led by Whiting-Turner, SGH performed condition assessments and helped develop enclosure repairs for several campus buildings.

SGH investigated the condition of seven buildings at Dumbarton Oaks. We completed interior and exterior surveys to identify damage and deterioration, made observations at exploratory openings to document concealed conditions, and performed water testing to determine leakage paths.


Working with the project architect, SGH developed building enclosure repairs for Acorn Cottage, the Director’s Residence, the Main and Guest Houses, Operations Building (OPS), Refectory, and Potting Shed buildings. Highlights of our repair designs included the following:

  • Replacing deteriorated felt underlayment and slate roofs to extend the useful life of the roof assembly and protect the invaluable contents
  • Testing existing slate to evaluate durability for reusing
  • Repairing cracked, loose, and displaced brick to maintain a durable wall
  • Replacing Guest House windows, Acorn Cottage doors, and the Main House skylight
  • Reframing dormer windows on the OPS building
  • Repairing stone panel and balustrade repairs at the Main House


We performed construction administration services, including the following:

  • Reviewing building enclosure submittals, shop drawings, and contractor requests for information
  • Visiting the site to observe ongoing construction to compare with the design intent and to assist with resolving unforeseen conditions
  • Water testing replacement windows to verify performance

Project Summary



Completion Date
Repair & Rehabilitation | Preservation
Building Enclosures | Applied Science & Research
Specialized Capabilities
Condition Assessments | Preservation | Environmental Simulations

Key team members

Niklas Vigener
Niklas Vigener
Chief Technical Officer