Shawn Brennan

Project Architect

HOK

Shawn T. Brennan, AIA

Shawn Brennan is a registered architect in HOK’s Atlanta studio with more than 15 years of experience spanning transportation, science and technology, government, higher education, and residential sectors. He excels in construction detailing and project oversight from concept through post-occupancy. Shawn is known for his hands-on approach, technical expertise, and ability to solve complex design challenges. His passion lies in delivering high-quality architecture through thoughtful execution and strong collaboration with clients and project teams.

Alex Hassell

Architect

HOK

Alex Hassell has over a decade of experience across science and technology, healthcare, government, K–12, higher education, and civic projects at HOK’s Atlanta office. He combines a strong technical foundation with a passion for high design, building lasting relationships with clients and colleagues. Alex is committed to delivering thoughtful, high-quality architectural solutions and fostering a collaborative environment. His work reflects a dedication to excellence and a deep understanding of diverse project needs and contexts.

Matt Breidenthal

Director of Engineering

HOK

Matt Breidenthal directs HOK’s Engineering practice, leading award-winning projects recognized for design excellence, creativity, and sustainable performance. A licensed PE/SE in most U.S. states, Matt has delivered billions of dollars in construction across global markets. He is known for innovative, interdisciplinary solutions and technical leadership. Matt serves on HOK’s Board of Directors, Design Board, and Marketing Board, and oversees the firm’s research program, shaping engineering strategy and driving excellence from concept through construction.

Mark Chiu

Vice President

Thornton Tomasetti

Mark Chiu leads Thornton Tomasetti’s Façade Engineering Practice in Chicago and has more than 16 years of experience in design of all types of exterior envelope systems, with a focus on sustainable design. He has in-depth knowledge and a specialization in building science, with certifications and credentials in the area of LEED design, NFRC simulations, and Building Enclosure Commissioning. His project work reflects this area of expertise as it involves attention to thermal analysis, high-performance and climate-specific design, and testing/analysis of the building envelope systems. He has collaborated on several notable national and international projects involving complex geometries, intricate detailing, challenging performance goals and material uses, as well as reuse of existing structures for re-clad/over-clad envelope design solutions.

Patricia Layton

Professor

Clemson

Pat Layton is the Strategic Advisor to Clemson’s Wood Utilization + Design Institute and a retired professor of forestry. She previously served for 12 years as the Institute’s founding director. She spent the first 14 of her 26 years at Clemson as Director of the School of Agricultural, Forest, and Environmental Sciences and chairing the Forest Resources and Forestry and Natural Resources departments.

Before joining Clemson University, she held various positions with the American Forest & Paper Association, Scott Paper Company, Oak Ridge National Laboratory, and Owens-Illinois. She served on the Board of the Sustainable Forestry Initiative for the last six years.

Pat is a native of South Carolina and has forestry degrees from Clemson University, Texas A&M University, and the University of Florida.

Mark Joyner

Associate Principal

Perkins&Will

AIA, LEED AP BD+C

Mark is technical at heart. As soon as he discovered that things could come apart, he became fascinated with how to put them back together. Today, his professional portfolio is composed of a wide range of academic-science buildings—projects that span various Science & Technology program types for higher education, federal, and private developers, integrating the complex technical needs of research facilities with human-centered spaces. He attributes his success to his curiosity, humility, and rigor, as well as his ability to absorb the pressure of high-stakes environments. Also a mentor at his core, he is committed to supporting the next generation of technical leadership in the studio. 

Mark learned to lead projects with confidence from his own mentor, Dan Watch, with whom he also learned to set ambitious goals. In almost two decades with the studio’s Science & Technology practice, he has only ever known one objective: to deliver the best science buildings in the world. To get there, he encourages every team to be fearless in meeting a client’s needs and vision, but also to be prepared. When a client’s needs change, the team will need to recalibrate quickly. Confidence comes not from knowing every answer, but from knowing his teams are ready to solve those challenges as they arise.  

And then there is the why. Mark makes sure to keep the purpose of every project in clear view, because knowing the why brings forward the most intelligent solutions for mission-driven spaces.