Paul Dannels

FAIA, Partner

“In the world of structural engineering, a job well done demands a presence that’s invisible most of the time, but then inspiring in the opportunities that remain.”

In his role at SDI Structures, Paul conceives innovative structural solutions for buildings on behalf of both aspiring and accomplished architects. His clients value his ability to quickly grasp complex architectural intentions and effectively render them in structural form. His designs have earned five IDEAS2 Awards from the American Institute of Steel Construction, the industry’s highest engineering honor for buildings constructed with steel. He also serves on the NASCC Steel Conference Architecture Committee.

Paul has taught engineering concepts to architecture students at the University of Detroit and Lawrence Technological University. He served as the 2014 President of AIA Michigan and in 2013 he was named a Fellow of the American Institute of Architects

Paul grew up in western New York, where as a teenager grand buildings like the Buffalo City Hall and Buffalo State Hospital captured his imagination. He studied engineering and architecture at the University of Michigan, and worked as a construction superintendent in remote northern Michigan before forming SDI-Structures.

Anders Sjogren

PE, Partner

"What I most enjoy is understanding an architect's vision, then crafting the quiet, elegant structure that brings it to life."

With more than 30 years of experience, Anders has become a leader in the engineering of collegiate athletics projects, as well as higher education, K-12, and healthcare facilities. He has built close working relationships with the architects and universities he has served. Driven by a passion for constant improvement, he has been instrumental in developing and implementing innovative BIM practices within the office. Beyond leading project design, he enjoys strengthening the technical tools and standards that support the entire firm.

Peter Heeringa

PE SE, Partner

"Structural engineering is our profession, but service is our purpose. We use engineering to help people solve problems, achieve their vision, and build relationships that endure."

After earning his engineering degree from the University of Michigan, Peter began his structural engineering career in Washington, D.C., where he designed healthcare, higher education, and government facilities. In 2013, he returned to Ann Arbor with his family and joined SDI Structures.

As a Principal at SDI Structures, Peter leads multidisciplinary teams through every phase of complex projects, from early planning and design through construction. With more than 18 years of experience across a wide range of structural systems and building types, he brings both technical depth and practical
perspective to every project.

Peter is recognized for his collaborative approach, his ability to communicate complex engineering concepts with clarity, and his commitment to delivering thoughtful, innovative solutions that consistently exceed client expectations. He believes engineering is ultimately a profession of service, using technical expertise as a means to help people solve problems, realize their vision, and build relationships that endure long after construction is complete.

Bill Toy

PE SE, Partner

“At the heart of structural engineering lies a passion for crafting environments that not only endure but also enrich the lives of those who inhabit them.”

With extensive experience in both institutional and commercial building design, Bill is committed to delivering cutting-edge structural engineering solutions. He actively contributes to the advancement of professional practice standards and sets a high bar for his team at SDI Structures.

Throughout his career, Bill has led numerous high-profile projects, including The Hadley Family Recreation & Well-Being Center, where his innovative use of structural steel showcased his ability to balance efficiency, aesthetics, and functionality.

Bill earned his structural engineering degree from California Polytechnic State University. Before returning to the Midwest with his family, he was a leader at a prominent West Coast consulting firm, where he honed his skills and developed a deep appreciation for collaborative, client-focused design.

Outside of work, Bill enjoys golfing in the summer and snowboarding in the winter. He is passionate about mentoring the next generation of structural engineers and actively participates in industry events and conferences to share his knowledge and experience.