We are proud to announce that Greg Frankenfeld and Andrew Gilles, trusted leaders who have grown with the firm, are now Principals at Mackey Mitchell Architects.

Both Greg and Andrew embody the values that define our practice: design excellence, technical rigor, collaborative spirit, and a deep commitment to client service. Their elevation reflects not only the leadership they bring to their teams and projects but also the lasting impact they’ve had on the firm and our culture.

Greg Frankenfeld (Left), Andrew Gilles (Right)

Greg Frankenfeld, AIA
As one of the principal leads in our Dallas office, Greg brings over three decades of architectural experience to his work. Known for his calm demeanor and organizational skills, Greg has a talent for guiding teams through complex projects with clarity and collaboration. Since joining the firm in 2008, he has played a vital role in delivering award-winning projects that balance vision with feasibility, thanks to his ability to address budget, schedule, and achieve stakeholder needs without compromising design integrity.

One of Greg’s earliest and most meaningful contributions was the South 40 Housing and Dining Center at Washington University in St. Louis—a 355,000 SF mixed-use campus project that earned LEED Gold certification, an AIA Midwest Construction Magazine Best of 2010 Award, and #1 ranking in Niche.com’s “25 Best College Dorms in the U.S.” He reflected, “It was my first project as a Mackey Mitchell employee … complex and on a tight schedule but incredibly rewarding. It was local, impactful, and a great way to begin my time at the firm.”

Washington University, South 40 Residential Community

Greg’s project experience highlights his curiosity, adaptability, and commitment to quality. At the University of Arkansas, he worked on Adohi Hall, the nation’s first large-scale mass timber residence hall and, at the time of completion in 2019, the largest cross-laminated timber (CLT) building in the U.S. This project achieved LEED Silver certification and received significant recognition, including the 2020 AIA St. Louis Honor Award, 2020 AIA Arkansas Honor Award, 2020 AIA Gulf States Region Merit Award, and additional design awards like the Wood Design & Building Honor Award and WoodWorks Multi-Family Design Award. Greg noted, “Working with mass timber was fascinating—I loved the opportunity to take on something new and challenging.”

University of Arkansas, Adohi Hall

Most recently, at Baylor University, Greg has led the renovation of Kokernot Hall, a 1940s residence hall full of character and complexity. “It’s been so rewarding to overcome the unique constraints to reinvigorate such an old building. I’ve really enjoyed working with the Baylor team. Despite the challenges, it’s been fun and memorable—and it marks our first significant ‘local’ Texas renovation project since establishing the Dallas office.” Construction is currently underway and is expected to be completed in summer 2026.

Baylor University, Kokernot Residence Hall

Andrew Gilles, AIA, LEED AP
With more than 23 years’ experience designing healthcare, research, K–12, and higher education environments, Andrew brings a wide-ranging and award-winning portfolio to his role as Principal. At Mackey Mitchell, he is admired for his ability to marry creative vision with technical depth, using advanced 3D visualization and immersive tools that help clients confidently envision the inspiring concepts being proposed.

Throughout his career, Andrew has worn many hats, from master planner to construction administrator, which gives him a comprehensive understanding of the entire design process. His curiosity and passion for exploration fuel his drive to solve complex challenges with elegant and meaningful solutions.

Andrew’s first project at Mackey Mitchell, the transformation of the Schine Student Center at Syracuse University, exemplifies his ability to revitalize underperforming spaces into vibrant community hubs. He collaborated closely with Principal John Burse, a proud Syracuse alumnus, and engaged thousands of students across campus to shape a shared vision for the reimagined center. The result was a bright, dynamic, 24/7 campus destination that earned both regional and national design awards and demonstrated Andrew’s skill in leading complex, high-impact projects from concept to completion.

Syracuse University, Schine Student Center

Magnolia Speech School was especially meaningful for Andrew, bringing his personal connection to education to the forefront. “As someone from a family of teachers, education projects are deeply personal to me—this one especially. The school’s connection to nature creates a uniquely peaceful and joyful place. The feedback from students, parents, and teachers about how this building has positively impacted their lives is a reminder of why we do this.” Working closely with a passionate client dedicated to transforming the lives of students with communication disorders, Andrew helped shape a nurturing, nature-connected learning environment that supports healing, growth, and joy. Hearing firsthand from families about the building’s impact remains one of the most rewarding moments of his career.

Magnolia Speech School

Andrew’s work has touched many sectors, but several projects stand out for their personal and civic resonance. His design leadership on the Central West End Metro Station in St. Louis earned top honors from both AIA Central States and AIA St. Louis, and redefined what public infrastructure can be. The project presented a bold opportunity to explore a new building typology and enhance the daily experience of thousands of riders with a dignified, safe, and inspiring transit environment. With improved amenities, visibility, and a welcoming presence, the station aspires to restore confidence in the city’s mass transit system.

Central West End Metro Transit Station

“These promotions mark an exciting moment for our firm,” said John Burse, FAIA, Principal at Mackey Mitchell Architects, who offered reflections on both Greg and Andrew.

“Building trust and earning client confidence depends on steadily navigating often challenging waters. Keeping both client and project team sailing on course and off-the-rocks demands both calm and rigor. Greg does this masterfully and fearlessly embraces new challenges, like making Texas his home and helping to establish our Dallas office,” Burse said.

Reflecting on Andrew, Burse observed, “What distinguishes a great designer from a good one? Being able to consistently conjure evocative yet achievable solutions born of challenging and complicated circumstances. If you combine that uncommon ability with a self-effacing sense of humor, you will know the joy of collaborating with Andrew.”

We are excited to welcome Greg and Andrew into their new leadership roles and look forward to the continued influence they’ll have on our practice, our projects, and the communities we serve.