onMain recently refreshed its master plan for the 38-acre space on the former Montgomery County Fairgrounds, west of Miami Valley Hospital and near the UD campus in south-central Dayton.
The vision is substantially the same: A mixed-use home for digital and technology-focused jobs and research, with residences, complementing the missions of UD, Premier Health, the Air Force and other stakeholders.
If you’re trying to make sense of the project, Heitkamp suggesting thinking of onMain as a “land developer.” The entity will develop “pads” for construction on the former fairgrounds, build infrastructure and lease those pads to long-term users.
“We want to hold this land into perpetuity,” Heitkamp said. “We’re not looking to chunk the land off to other developers. We want to control that quality of development.”
Construction is underway on the site’s first building, and Heitkamp hopes to see work start by the end of the year on about 200 units of multi-family residences, to the north of the first building.
Expect more pads along Stewart Street, but expect also space for a retention canal, recreation and, in time, a new openness that longtime residents may find disconcerting at first.
The fence that protected the site for decades will be removed, Heitkamp said.
Nearly a decade ago, UD and Premier, owner of Miami Valley Hospital, banded together to buy the property for $15 million after the fairgrounds moved to Infirmary Road.
A lot has happened since then. In 2024, the site earned a designation as an Ohio “Innovation Hub,” the state’s second— and with it $35 million from the state.
A Skanksa-Shook joint venture construction team last fall started work on the site’s first building — a $75 million, five-story, 120,000-square foot building that Shook’s chief operating officer recently predicted “will turn heads” at Main and Stewart streets.
With an anticipated opening in the second quarter of 2027, the building (dubbed “Think Dayton”) will be home to industry, Air Force researchers, academics and others.
“The uniqueness of the building really sets it apart in our region,” Heitkamp said.
Air Force personnel will have “specialized secure space” on the building’s fourth and fifth floors, with companies and academia working on middle floors and the public being most welcome on the first floor.
“We can’t just create this nice-looking building without the programming that goes inside,” he added. “And that’s just critical, and why the work with the Air Force and some of the sponsorship from the Air Force will allow for that programming to happen.”
Air Force needs informed the building’s design, he said.
One of the first tenants expected in Think Dayton: the Digital Transformation Center, or DTC, operated by the University of Dayton Research Institute.
The DTC officially opened in 2023 on the second floor of 1520 S. Main St.
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