13. Irgens
| Address | 648 N. Plankinton Ave. Ste. 200 |
| City | Milwaukee |
| State | WI |
| Zip | 53203 |
| Website | www.irgens.com |
| Phone | 414.443.0700 |
| Officers | Mark F. Irgens, CRE, CEO & Manager; Jaclynn Walsh, EVP & COO; Duane Nolde, CPA, EVP |
| Office Space Developed | 780,000 |