Renderings for the new development of 100 Mill, a Hines and Cousins joint venture, have been released.

Hines, the international real estate firm, and Cousins Properties, an Atlanta-based REIT, are under contract to purchase land and develop 100 Mill Avenue. The 2.5-acre site will include a new 15-story modern office tower, and also a hotel or apartment complex on a mixed-use site at Rio Salado Parkway and Mill Avenue with construction beginning Q2 2019. In addition, Hines and Cousins will convey the soon-to-be rehabilitated Hayden House, the historic home of former Arizona Sen. Carl Hayden and later the restaurant Monti’s La Casa Vieja, to the City of Tempe to use as it wishes.

“Hines is thrilled to collaborate with Cousins Properties, well-known for high-quality projects and experienced team members, to develop a trophy office building and a hotel or multifamily complex at this iconic location. 100 Mill will continue to enhance the City of Tempe’s robust skyline and add to the area’s economic vibrancy,” said Brandon Dillingham, director of development for Hines’ Arizona office.

“Cousins is looking forward to another successful partnership with Hines to develop 100 Mill Avenue,” said Colin Connolly, President and Chief Operating Officer of Cousins. “We are excited about the opportunity to add this future development to our best in class Tempe portfolio of Hayden Ferry Lakeside, Tempe Gateway and 111 West Rio.”

The Hayden House, located on Rio Salado Parkway and Mill Avenue, was built between 1871 and 1873 as a Sonoran row adobe house, according to the City of Tempe. In addition to serving as the Hayden family home, it was a boarding house and later a restaurant. Hensel Phelps Development of Greeley, CO., which is selling the site to Hines and Cousins, is presently renovating the house in an intricate process that involves historic techniques such as drying adobe bricks.

“Hensel Phelps is committed to being good stewards of the Hayden House. We are honored to rehabilitate such an iconic location for the City of Tempe and Arizona. We are pursuing this important assignment, led by our architectural partner Motley Design Group, with the goal to return the structure to a condition consistent with the period of significance designated by Tempe’s Historic Preservation Committee and preparing it for future community use,” said Laird Heikens, president of Hensel Phelps Development.