Leadership Role: Principal
Tim Sepper, PE, SE
Darin Amsberry, PE
Darin is a Principal with Farnsworth Group’s Advanced Manufacturing & Technology (AMT) practice and is passionate about designing high‑purity facility systems while delivering exceptional client experiences. He has spent much of his career supporting semiconductor fabrication clients, bringing deep technical expertise and a strong understanding of complex manufacturing environments. [office.com]
Darin specializes in ultrapure water and wastewater treatment systems, process chemical and mechanical systems, and controls. His experience includes both large‑scale renovation and upgrade projects as well as greenfield, new‑construction facilities. Known for his thoughtful, client‑focused approach, Darin works closely with teams and owners to deliver reliable, high‑performance process solutions that support demanding operational requirements.
Charles Keefer, AIA, NCARB
Charles brings more than 25 years of experience in architecture, project management, and organizational leadership. As the lead Principal based in Farnsworth Group’s Phoenix office, he focuses on comprehensive team leadership, project management, and QA/QC oversight to help ensure consistent, high‑quality project delivery.
Charles has managed a diverse portfolio of projects across multiple sectors, including complex health care, K‑12 education, higher education, and industrial facilities. His broad experience across clients, delivery methods, and project settings allows him to anticipate challenges early and guide teams toward successful outcomes. Known for his collaborative leadership style, Charles is committed to building long‑term client relationships and delivering thoughtful solutions that support both owners’ goals and the firm’s continued success.
Wade Ross, PE
Wade Ross is the Managing Principal of Farnsworth Group’s Building Engineering Systems Group, bringing nearly 30 years of experience in mechanical engineering. Wade has a diverse background in numerous market sectors, including government, healthcare, educational, manufacturing, and critical operations centers. Wade has demonstrated a history of working in the vertical building engineering industry and is a strong business development professional skilled in HVAC, Plumbing, Ventilation, Consulting Engineering, and Fire Protection.
Wade holds a BS in Mechanical Engineering from Iowa State University and is dedicated to developing healthcare, industrial, and education projects. His ability to combine technical expertise with strategic business development enables him to drive organizational growth and deliver exceptional results.
Scott Throm, PLS, RLS, CFedS
Amanda Occhi, PE, LEED AP
Amanda is a Farnsworth Group Principal and Professional Electrical Engineer with more than 20 years’ experience in the design and construction of healthcare, municipal, federal, educational, and advanced manufacturing facilities. She serves as Section Leader for Farnsworth Group’s Electrical West group, bringing a wealth of lighting, power, and systems design experience. She is a LEED Accredited Professional, Building Design and Construction and is passionate about energy efficiency in conjunction with the principles of good design. In her free time, Amanda loves to run, hike, camp, ski and snowboard, and hang out with family and friends.
Jeff Chermely, AIA, NCARB, LEED BD+C
Jeff Chermely is the Architecture Group Leader and a Principal at Farnsworth Group. He is a licensed architect with over 20 years of experience. Jeff has delivered award-winning projects in a wide variety of markets including corporate office, K12 education, healthcare, sports and recreation, and life science. This wide range of experience, complemented with advanced degrees in business and construction, allow Jeff to manage complicated projects from concept to construction closeout.
Scott Janssen, PE
Bob Ridgway, AIA, NCARB
Bob is a Farnsworth Group Principal and brings more than 35 years of experience to his role as Principal in Charge, providing leadership, oversight, and quality assurance across all aspects of architectural design. He serves as a primary point of contact for clients and project teams, guiding projects from early planning through completion. Bob works closely with clients and team members to coordinate schedules, manage in‑house resources, and ensure project goals are clearly understood and met. He has successfully partnered with organizations such as the Iowa Department of Administrative Services, Iowa correctional facilities, and the Iowa Fire Marshal’s Office, completing a wide range of projects for both new and existing buildings. Known for his hands‑on approach, Bob is involved throughout the entire project lifecycle, tailoring each design to meet the specific needs of the client and community.