29 and 31 Newbury Street
The brownstone row houses at 29-31 Newbury Street were built between 1872 and 1874 and are contributing structures in the Back Bay Historic District. The facades are composed of Portland Connecticut brownstone, a material known for its poor durability. The brownstone exhibited significant deterioration, lost significant section and much of its architectural detailing, and posed a potential falling hazard in some areas. SGH helped developed a comprehensive facade restoration program that restored the original appearance of the building and improved durability.
SGH assessed the condition of the brownstone row houses with Italian Renaissance Revival detailing, bracketed wood and sheet metal cornices, and slate-covered mansard roofs. We determined that, while the brownstone deterioration was severe, the depth of the remaining sound stone was structurally adequate.
We tested the brownstone in our laboratory, determined the significant material properties, and conducted tests and mockups. Using the results from the laboratory testing, we developed the repair mortar composition by incorporating brown Connecticut River Valley sand to match the color of the stone.
Ten years after its completion, the project was presented as a case study of a durable, color-fast, aesthetically appropriate brownstone repair at the Association for Preservation Technology International Conference.