About Us
Our Story
Nationally recognized as a leader in civil & structural engineering solutions for over 20 years, Mainstay Engineering Group, Inc. has been at the forefront of providing engineering solutions to life sciences and high-tech, mission critical companies since its founding in 2002.
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Mainstay began with a focus on servicing Life Sciences. Over the years, we have grown to a team of licensed experienced professionals and Subject Matter Experts (SMEs) servicing partners and clients throughout the United States in a wide variety of essential services industries.
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In January 2025, Mainstay proudly welcomed Professional Engineering Associates (PEA) of South Carolina into our organization. This strategic acquisition unites two highly respected engineering firms, combining over 40 years of expertise in civil and structural engineering. Together, we strengthen our commitment to delivering innovative, client-focused solutions for mission-critical industries while expanding our reach and capabilities to better serve our clients.
Our design professionals are licensed to perform engineering services in the United States, but our reach extends beyond borders, having performed consulting services internationally. Today, 85% of our portfolio comprises Mission Critical projects, a testament to the trust our clients place in us for their most important projects.
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The Mainstay Difference
Our team's relentless pursuit of excellence is fueled by a unique, multi-disciplined approach to anticipate our clients' needs and provide creative and flexible facility design solutions that optimize every project.
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Health & Safety
Mainstay upholds the highest safety standards, especially when working with mission critical, life sciences and pharmaceutical clients. We are regularly recognized for our numerous safety awards, and most recently earned the prestigious 2023 Highwire Gold Award for Safety. This achievement reflects the unwavering commitment and dedication of every individual at Mainstay to creating a workplace that prioritizes safety above all.
Our Approach & Core Values
Mainstay's Mission
Empowering progress through exceptional solutions that build for the future and impact lives.
Values
Our core values form the bedrock of Mainstay’s culture, guiding us in every aspect of our work. And, our commitment to diversity, equity and inclusion is core to who we are as a company and enables us to better serve our clients and partners. We recognize the value of fostering an inclusive and equitable work environment – one that fosters diversity of opinion, innovation, and creates a workplace that reflects the communities we serve.
Transparency
Commitment
Responsiveness
Curiosity
Excellence
Our History
Mainstay's journey began in 2002 with a singular mission; to redefine the landscape of civil and structural engineering services. Founded by Matthew E. Hilbush, P.E., Mainstay Engineering started with a niche identity in the pharmaceutical sector. This laid the foundation for a remarkable journey to becoming one of the leading engineering firms in the country.