Sponseller Group, Inc. stands as a versatile engineering firm with established offices in Holland and Sidney, Ohio. Our commitment extends beyond projects; we foster a collaborative environment that empowers our team to grow, expand their expertise, accumulate valuable experiences, and progress in leadership.  

Within the structure of Sponseller Group, Inc., our diverse personnel census encompasses professional engineers, graduate engineers, senior designers, and mechanical designers. Each department comprises of a manager, structural engineers, designers, and CAD personnel. Our corporate culture actively supports and encourages every staff member in their professional pursuits, personal accomplishments, and community engagement.

Sponseller Group’s main office is located in Holland, Ohio.  We moved into this bespoke newly designed office in 1998.  The 10,000 sq. ft. office houses about forty of our sixty four people from the various disciplines of civil, structural, mechanical ventilation, electrical, and mechanical system design.

The primary focus areas of our company encompass structural engineering, industrial architectural design, structural design, and facilities mechanical and electrical design, making them the predominant service offerings. The majority of our project assignments are executed in our two offices situated in Holland and Sidney, Ohio. In addition, we collaborate with general contractors and fabricators by delivering comprehensive engineering and design services. Thankfully, over eighty-five percent of our projects originate from repeat business with our existing clients.

Our objective is to offer quality engineering services at a reasonable and fair price, ensuring client satisfaction. With a track record spanning several decades, we’ve established strong relationships with numerous clients. At Sponseller, we acknowledge the central role of advanced analysis and design software, coupled with robust computing systems, in delivering optimal solutions to your challenges.

Our team of engineers and designers is dedicated to collaborating with clients from project inception to completion. We proactively identify and address potential difficult problems that may arise, even those not immediately apparent. Constantly engaged with clients, we contribute to enhancing operations for the next generation of products or improving current production processes.

What distinguishes us is our extensive experience, commitment to client needs, and timely responsiveness. Our employees enjoy long-lasting careers thanks to our inviting work environment, supportive colleagues, competitive salaries, comprehensive benefits, and refreshed workstations equipped with the latest software. We value and generously compensate new hires based on their experience and education.

 A short history of Sponseller Group

Harold Sponseller transitioned from his role at Owens-Illinois in research and development to pursue new opportunities. He ventured into drafting work, eventually finding enough assignments to match his previous income of approximately $27,000 annually. Balancing job hunting during the day with drafting projects in his basement at night or the following day, Harold’s journey began near the University of Toledo on Dorr Street, where he established his first office, spacious enough for a team of five. Among the initial hires were Mark Sponseller and Mark Buchanan. His tasks ranged from mechanical drafting to creating illustrations for Dana Transmission catalogues.

The company expanded, leading to a second office at Byrne and Hill, specializing predominantly in machinery design. Clients often requested on-site assistance, leading to the employment of seven individuals at Midland-Ross Surface Combustion and thirteen at Owens Corning Fiberglas. Over time, Harold diversified services to include structural steel detailing, engineering, and design. Notable projects included the substantial structural steel drafting for McNally Pittsburg, to be used in China.

Eventually we were able to obtain some from GM Defiance, and the structural group flourished. With the addition of talents like Dave Nowak, Frank Miller, Doug Wott, and Kevin Nevius, the team expanded its capabilities. The journey continued with the establishment of subsequent offices, from Maumee’s 1446 S. Reynolds Road to our current location at 1600 Timber Wolf Drive in Holland and 1516 Target Drive in Sidney, Ohio.

Our growth was fueled by a commitment to excellent service at reasonable rates. Harold’s approach was grounded in developing ideas from scratch, covering all aspects from finding work to managing invoicing, payroll, and benefits. By focusing on clients within a 1–2-hour drive of Toledo, we avoided the nomadic nature of industries like glass manufacturing, prioritizing the stability for our team members. This philosophy reflected Harold’s desire to foster a family supportive work environment.

Mission Statement

We aim to offer manufacturers, fabricators, and contractors top-tier engineering and design services. Our commitment extends beyond delivering exceptional work; we prioritize providing meaningful employment and abundant benefits to our dedicated team and their families. We ensure competitive compensation, aligning with or surpassing other local engineering firms, fostering a rewarding and sustainable professional environment.

Quality Objective

To meet client expectations on accuracy, content, and delivery, we take responsibility and work to resolve any issues that may arise.


Our people are trained with all the required safety training for lockout/tagout, fall protection, lift training, confined space, first aid, AED/CPR, and mine safety.

View Our Service Offerings


  • Integrity & Honesty – We stand by our commitments and take responsibility for any mistakes or oversights.
  • Safety First – We prioritize the well-being of our team members and yours, whether in our office or on-site.
  • Respect – We respect everyone from clients and employees to subcontractors. 
  • Attention to Detail – We ensure precision and timeliness in delivering accurate drawings.
  • Leadership – Strive to be a leader at work, home, and in our community.
  • Commitment – Dedicated to the success of our clients and employees.
  • Competency – Our team comprises of qualified professionals with extensive experience.
  • Teamwork & Flexibility – Collaboration is key, and we always strive to find solutions to challenges by being flexible and adaptable.
  • Financial Strength – With five decades of operation, our company has a solid foundation for sustained success.
  • Professionalism – Maintaining a professional demeanor with clients, employees, and subcontractors.  

Community Involvement

Sponseller Group supports the community through WISE – Women in Science and Engineering, WGTE public television, Cast Metal Association, Boy Scouts of America, University of Toledo car competitions, Whiteford High School Robotics Team, United Way, MS Foundation, and other organizations.