Los Angeles, CA

Mount St. Mary's College, Doheny Mansion


Built in 1899 for the Oliver P. Posey family, the Doheny family occupied the home for nearly sixty years.  The three-story mansion was designed by architects Theodore A. Eisen and Sumner P. Hunt with elements from the Gothic, Chateauesque, Moorish, and California Mission styles.  Now part of the Mount St. Mary’s College downtown campus, the structure is a Designated Historic-Cultural Monument for the City of Los Angeles.  Historic Resources Group retained SGH to prepare the building enclosure, materials conservation, and waterproofing portions of their report for the Doheny Mansion.

SGH performed a visual survey of the mansion exterior.  We noted the following:

  • Wood-framed exterior walls are clad with plaster, ornamental cast plaster, marble, and sheet metal
  • Prominent features of the Doheny Mansion are a Tiffany glass dome, numerous wood balconies, and a wooden tower above the main entrance
  • The main skylight covers the Tiffany dome, and acrylic skylights are located throughout the low-sloped built-up roofs, pitched clay tile roofs, and at the east entry canopy

For this project, SGH’s work included the following:

  • Water tested to confirm leak paths
  • Conducted paint adhesion tests
  • Documented concealed conditions of the exterior wall construction at exploratory openings construction
  • Analyzed exterior plaster in our laboratories
  • Recommended immediate and long-term repairs, maintenance, and further testing
  • Wrote the exterior walls and roofs portions of the Historic Structures Report

Project Summary



Completion Date
Repair & Rehabilitation | Preservation
Building Enclosures | Applied Science & Research
Culture & Entertainment
Historic Resources Group
Specialized Capabilities
Condition Assessments | Preservation | Physical Testing | Environmental Simulations | Materials Science

Key team members

Carolyn Searls
Carolyn Searls
Senior Principal