Our History

Tracing its roots to 1954, O’Donnell & Naccarato is one of the oldest and largest consulting structural engineering firms headquartered in Philadelphia. O’Donnell & Naccarato’s predecessor, Seymour Greenberg, opened a consulting structural engineering practice in Philadelphia in 1954. Villanova University classmates William F. O’Donnell and Peter A. Naccarato joined the firm as principals – O’Donnell in 1968, when the firm became incorporated, and Naccarato in 1974. In 1981, the corporation, known originally as Greenberg, O’Donnell & Naccarato, reorganized and the present name O’Donnell & Naccarato, Inc. was adopted.


William F. O’Donnell (left) and Peter A. Naccarato, May 1988

As the firm grew in the following decades, O’Donnell & Naccarato expanded its reach to provide structural engineering services to clients throughout the Mid Atlantic region and across the United States. In 2001, O’Donnell & Naccarato opened a Bethlehem, PA office to serve the Lehigh Valley. In 2003, the firm began the first phase of an ownership transition plan by adopting an Employee Stock Ownership Plan (ESOP) to become an employee-owned firm. President and CEO, Nick Cinalli was joined by a leadership team of principals – Anthony Naccarato, Mark Lunden, Peggy Hart and Dennis Mordan. The next phase of leadership transition occurred in 2013 when Anthony Naccarato was named President. Later that year, O’Donnell & Naccarato opened a Mountainside, NJ office led by Principal Paul Panzarino to serve the New York Metropolitan area. In 2014, O’Donnell & Naccarato structural engineers Scott Bauer and Michael Herrmann joined the firm’s senior leadership team as Principals.

Our Present

Today multiple divisions complement our core practice of structural engineering. We offer dedicated practice areas in facade restoration, garage restoration and parking consultation. O’Donnell & Naccarato is recognized for its expertise designing and managing projects of all sizes, types and levels of complexity. Its leadership in employing advanced technology to provide cutting-edge designs, pragmatic solutions and timely deliverables has set O’Donnell & Naccarato apart in the AEC community.