Our story

In the early 1970s, Bob Sprengeler, the founder of LSEngineers, embarked on a remarkable journey. Leaving behind a thriving structural engineering firm in Minneapolis he decided to move to the countryside. His motivation was deeply personal, seeking to provide his family with a rural upbringing akin to his own childhood in Janesville, MN. Le Sueur was a bustling city in the heart of Minnesota within easy driving distance to the Twin Cities metro area and several growing regional centers. A perfect fit, Bob took on the role of city engineer and embraced the welcoming local community.

Yet, Bob’s passion for structural engineering consulting never ceased. He decided to rekindle his passion and open a branch office via his former employer, not realizing he was laying the foundation for what would become LSEngineers, Inc. The following year brought Bill Lehnertz into the company, and together they began to build a respected enterprise known for tackling and solving fascinating structural puzzles.

Gene Dwyer joined the firm in 1987, adding his unique expertise to the mix. In 1989, the firm’s consistent growth and reputation for integrity and comprehensive service led Lehnertz and Sprengeler to establish LSEngineers, Inc. Eight years later, in 1997, Brian Salfer, another exceptional talent, commenced his career with LSEngineers, further enriching the company’s legacy.

Throughout the vibrant and technological advancement of the past 35+ years, LSEngineers continues to grow, thrive and evolve. LSE is now recognized as a structural consulting firm noted for its innovative solutions and expertise. Our team, led by Gene and Brian, is comprised of five licensed engineers and an incredible support staff, each with vast experience, collectively totaling over two centuries of knowledge. Our renowned technical drafting technicians diligently craft the intricate construction drawings that embody LSEngineers’ commitment to excellence and comprehensive service.


Green Building Certification Inc. (Certified LEED AP BD+C)

American Concrete Institute

American Society of Civil Engineers

International Code Council

Minnesota Concrete Council

Minnesota Historical Society

Minnesota Society of Professional Engineers

National Council of Examiners for Engineers & Surveying

National Society of Professional Engineers

Society of Women Engineers

Structural Engineers Association of Illinois

South Central College Architectural Drafting & Design Advisory Board

Associated Builders and Contractors Award Judging Committee