NAI United has been Sioux ' top producing commercial real estate firm since our first full year of business in 2006. Proven track records, along with deep local knowledge and exceptional customer service, makes us the go to for commercial real estate. The NAI United team offers a full range of brokerage services for business, industrial, investment, land, office and retail properties, lease administration, owner and tenant representation, corporate relocation, and property management. NAI ' agents have decades of real estate experience and have earned some of the ' top designations such as Society of Industrial & Office Realtors (SIOR) and Certified Commercial Investment Members (CCIM).