What We Build,

Builds Us All

What we build

builds us all

About Greiner

At Greiner we don’t just construct quality environments, we build lasting relationships with our clients and the greater community. We are built on a strong foundation of human connection; one in which our team is committed to reaching your goals while offering guidance and education along the way. From occupied remodels and interior renovations to ground-up new construction projects, our team collaborates with you to create innovative, liveable spaces to fit your needs.

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“Thank you very much for the depth of attention you are giving the LifeSource project.... It is clear to me you take pride in your work and take pride in our partnership.”
—— LifeSource
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in Practice


Our web series offers viewers and listeners alike an opportunity to experience conversations and insights from some of the industry’s finest. Be sure to follow us on social media to stay up to date on all things construction.

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Hans Siefker

Hans Siefker

Construction Management degree with a double-minor in Business and Interior Design from Minnesota State University, Mankato.

LEED Accredited Professional.
40 Under 40 Award Recipient.
Started his construction career and with Greiner in 1998.

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Senior Project Manager

Bachelor’s degree in Construction Management from North Dakota State University.

LEED Accredited Professional.
Started his construction career in 1996.

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Director of Business Development
Heather Weerheim

Bachelors of Science in Housing Studies from the College of Human Ecology from the University of Minnesota, Minneapolis.
Started her construction career in 2006.

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Senior Project Manager

Bachelor of Science in Construction Management degree from Minnesota State University, Mankato Minnesota.

LEED Accredited Professional.
Started his construction career in 2002.

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Josh Miltenberger

Construction Executive

15 years of commercial construction experience, almost exclusively in markets across the state of Iowa.

LEED Accredited professional

B.S. in Construction Engineering from Iowa State University.

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Community Involvement

Construction may just be the beginning for us, but it doesn’t stop there – we place a large emphasis on giving back through various sponsorships, donations, and events all in an effort to better our community.

The Next Chapter

Greiner is growing with a new office in Des Moines, IA. With multiple projects under our belt we are excited to continue developing and building upon our relationships in the Hawkeye state. Read more about our regional growth here.