Day & Zimmermann Recognized as One of ENR’s 2024 Top 500 Design Firms

PHILADELPHIA, PA., May 9, 2024 – Day & Zimmermann (D&Z), the century-old, family-owned provider of construction, engineering, maintenance, staffing and defense solutions for leading corporations and governments around the world, has been recognized as one of 2024’s Top Design Firms according to Engineering News-Record (ENR). Day & Zimmermann is ranked #320 out of 500.

ENR brings structure to the construction industry by performing annual surveys of its key segments, and ranking companies engaged in general contracting, specialty contracting, engineering, architecture, and environmental services, among other specialties. The Top 500 Design Firms list, published annually in April, ranks the 500 largest U.S.-based design firms, both publicly and privately held, based on design-specific revenue.

“We’ve been positioning Day & Zimmermann’s Maintenance and Construction division under an EPC execution model to help our customers in the power, industrial, and government markets advance their large-scale design-build projects,” said John McCormick, President of D&Z’s Maintenance and Construction division. “To be among ENR’s Top Design Firms for 2024 is an honor that speaks to that growth and our resulting success in bringing our customers’ big ideas to life.”

This year’s report, titled Artificial Intelligence Ramps Up, reveals a shift in the use of artificial intelligence to complement design services. Last year, AI was the exception more than the rule, but this year more design professionals aim to integrate tech into operations. With ongoing labor challenges, rising interest rates and supply chain disruptions still driving up construction costs, firms say AI could be the X factor that helps projects stay profitable.

“Day & Zimmermann is proud to be recognized among ENR's Top Design firms, providing best-in-class architecture and engineering services to the federal government worldwide,” said Ben Lilly, President of Mason & Hanger, a Day & Zimmermann company that provides architecture and engineering design services. “This recognition is meaningful to our teams because it aligns with our mission of Building a More Secure World, as we provide innovative solutions for difficult and complex design challenges to support the U.S. Government with their mission-driven facilities.”

To read ENR’s Artificial Intelligence Ramps Up report, along with the full Top 500 Design Firms list, visit:



When you’ve been around for more than a century, you learn a thing or two. At Day & Zimmermann, we take our lifetime of experience and make things better. Our 43,000+ employees help bring big ideas to life every day. We’re pushing the boundaries of innovation in construction & engineering, operations & maintenance, staffing, and security & defense. And that’s not all. Did we mention that we have 150+ worldwide locations with $2.7 billion USD in annual revenue? We put people to work, we protect American freedoms, and we help our customers power and improve the world. We do what we say®