O'Donnell & Naccarato

O’Donnell & Naccarato is a structural engineering firm founded in 1979 and headquartered in Philadelphia, with offices across the Northeast and Mid-Atlantic. The firm handles building structures, facade engineering, and structural investigation and restoration for healthcare, higher-education, commercial, and cultural clients. It served as structural engineer of record on the new acute care tower at Geisinger Wyoming Valley Medical Center in Wilkes-Barre, an 11-story, 600,000-square-foot hospital addition. O’Donnell & Naccarato’s practice runs from new towers to the forensic work of assessing and repairing existing structures, a mix that has grown as aging buildings face tougher inspection standards.

O’Donnell & Naccarato was founded in 1981 by Bill O’Donnell and Pete Naccarato and has grown from a three-person Philadelphia shop into a national structural engineering firm with over 100 professionals working from ten offices. Beyond the Philadelphia headquarters, the firm operates in New York, Mountainside NJ, Miami, Orlando, Indianapolis, Columbus, Cleveland, Pittsburgh, and Durham NC — a footprint built partly through acquisitions like McComas Engineering in Indiana and Douglas Wood Associates in Florida.

The firm is employee-owned; nearly all staff belong to the ESOP established through a transition that began in 2003, and the company frames that ownership as the reason for its client-relationship focus. Its engineers are registered in 49 states, and it averages more than 1,000 projects a year across every major construction sector — corporate, cultural, education, healthcare, hospitality, industrial, municipal, residential, retail, science and technology, senior living, and parking structures.

O&N works on both new structures and existing ones, handling expansion, renovation, and restoration. A distinctive capability is its building-envelope practice: after consulting on Philadelphia’s Façade Ordinance in 2010, the firm established a Rope Access Team for facade inspections and repairs. The 2019 McComas acquisition added specialty engineering for precast concrete, cold-formed steel, and aquatics structures.