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Principle Design + Engineering is a driven, family-owned, and operated design firm located in upstate New York, providing creative solutions, with perspective design and engineering. 

Principle Design maintains only one office, with a compact staff of licensed professionals, graduate engineers, architects, and specialty designers. We lack the size and flash of large firms, and instead, provide hard-work; attentiveness; and commitment; our resources match those of a large firm, but with the care of a small company.

Our compact nature and diverse group of professionals, allows us to be very effective and competitive in engineering/architecture and its related fields. We self perform all design work in-house, seldom using subconsultants. From the conceptual planning and approvals, through the final architectural, structural, civil, mechanical and electrical systems design and construction oversight.  We strive to work at competitive fees, and work to make projects cost effective and appropriate for their needs.

Principle’s comprehensive history of building related design services is robust and demonstrated. Throughout our firm’s history, and in conjunction with our staff’s experience, we’ve successfully completed everything from small renovations projects, through multi-million-dollar commercial buildings and developments. Our experience has included everything from multi-unit housing, retail buildings, banks, restaurants, performance theaters, municipal buildings and fire stations, office complexes, hotels, car dealerships and alike.

Working with State and Federal funding sources has been a key component for most – if not all -of our larger projects. Working extensively to assist with funding procurement, overseeing and assisting with application and execution of the project. We are very familiar with the necessary processes required, coordination with State Agencies and funding sources, MWBE requirements, and paperwork necessary to see the project through completion.

About: About


  • Metal Architecture Magazine - 2022

  • Design Cost Data Magazine -2020

  • Metal Construction News -2020

  • Roofing Magazine - 2020

  • Design & Build with Metal -2020

  • MBCI Metal, Inc. – Project Recognition 

  • CHI Doors, Inc. – Project Recognition 

  • Andersen Window – Project Recognition

  • Mohawk Flooring – Project Recognition

  • LG HVAC – Project Recognition

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About: Testimonial

Mike's experience spans over 20 years in Architectural, Civil, and Development Engineering. Compounding with over 40 bridges, 20+ municipal garages, and numerous other projects. Mike's experience ranges from Corporate Architectural and brand development, Automotive Museum Design, to Commercial Development.

Michael O'Reilly, PE

Dan's experience spans 12 years in Architectural, Mechanical, and Facility Engineering. This includes successful projects from Commercial VRFs, Pool Dehumidification, and Commercial Hydronic Systems, to full-facility MEP designs. Dan's experiences range from 40,000 sq-ft youth recreation centers to community Fire Stations.

Dan O'Reilly

MaryLu's combination of experience spans 30+ years in corporate administration, with an additional 5 years of A/E job oversite. MaryLu specializes in construction contract preparation and bidding oversight.

MaryLu O'Reilly

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