Experience, visionary thinking, and a shared commitment to client-focused project delivery.

Hans Siefker

Principal & President

Hans believes in reinforcing a culture where teamwork, collaboration, fun, and personal growth are staples of the company culture. Leading by example, he promotes an environment that encourages everyone to do the best they can, with a focus on delivering outstanding customer service and actively listening to understand the needs of each client.  

Spencer Finseth

Principal & Preconstruction Manager

Spencer is a visionary, always looking toward the future of the industry. His favorite part of the job is empowering clients through education and partnership. Spencer is a passionate advocate for increasing equity and inclusion in construction, and he serves on the boards of several nonprofits throughout the Twin Cities.

Kate Carlson

Administrative Director

As Administrative Director, Kate's role touches every facet of Greiner's work. She holds almost two decades of institutional knowledge and ensures a strong foundation and culture of excellence throughout the company. Kate manages multiple departments and corporate initiatives, setting a high bar for every team she leads.

Tom Hochstaetter

Principal & Operations Manager

Tom has an incredible will to succeed. That is a real advantage to his clients who quickly learn that Tom will do everything he can to give them what they need -- no matter what the challenge. Service is in Tom’s DNA, and it inspires everyone around him to deliver a successful job expertly done.

Josh Helgesen

Principal & Field Operations Manager

Josh began his career as a union carpenter and came to leadership after 20 years in the field. He knows exactly what it takes to run a successful jobsite, and he holds the field team to the highest standard. He has a long track record of exceptional results and satisfied clients.

Josh Miltenberger

Construction Executive

Josh provides senior leadership to the project teams and leads our Iowa office. With almost 20 years in the industry, he has completed work for clients across the state, with a focus on central Iowa. Josh has strong connections to the community; he is active with several non-profit and volunteer organizations in the Des Moines area.