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1401 Arch

Philadelphia, PA

One City Plaza at 1401 Arch Street is listed on the Philadelphia Register of Historic Buildings and was originally constructed in 1898 with an addition adding the two penthouse floors in the 1920s, extending the building along Arch Street, adding an elevator tower on the North elevation and constructing a one-story addition inside the courtyard. O’Donnell & Naccarato is currently providing structural engineering services for the conversion from a commercial building to a multi-family residential. Following our comprehensive facade assessment in January 2017 that identified severe terra cotta masonry deficiencies, severely deteriorated steel framing supporting projecting cornices, deferred maintenance, and brick deficiencies, we prepared construction documents to assist the owner to preserve the facade while maintaining the buildings unique ornamental architecture. The facade design consisted of replacement of portions of the projecting terra cornices with alternative terra cotta replacement units, replacement of the specialized brick, metal through-wall flashing improvements, and assistance with the window repairs and replacement. We are currently providing construction administration services during the facade rehabilitation project which is scheduled for completion in 2020. 


Structural System

Structural Steel with clay tile flat arch floors


Building Height/# of Stories

220′-0″ and 14 stories


Façade Material

Mass masonry wall with roman brick veneer and ornamental terra cotta