After six months of controversy, the council has tentatively approved the Laniers' planned $513-million, 607-acre Mundy Mill mixed-use project, one of the largest enterprises of its kind ever attempted in this largely rural northeast Georgia city, 40 miles from Downtown Atlanta.

The council's approval came after REL Properties increased its land donation offer to the Gainesville City School System by two acres for a total 17 acres, plus an additional 2.6 acres that can be kept as green space and used indefinitely by the school system.

The 17 acres have an estimated market value of about $2 million, area industrial brokers familiar with this suburban submarket tell GlobeSt.com. They base their estimate on a projected land value of about $100,000 per acre or roughly $2.30 per sf. Robby Lanier, a partner with his father, Robert Lanier, in REL Properties, says the additional 2.6-acre parcel could be purchased by the school system "at fair market value" in the future.

The Laniers' previous offer to the school system was a donation of 15 acres, as GlobeSt.com previously reported. The tract is between Mundy Mill and Mountain View roads and Meeks and Old Oakwood roads. REL is requesting a rezoning and annexation of the site by the city.

"This site will be a great location for an elementary school, tying into our existing green space plan," Robby Lanier says. "Our offer provides more than enough land to build the school and creates a connection to the trail network that will run throughout the community. We've said all along that REL is committed to being a good corporate citizen, and we want to do something good for the school system."

The master plan for Mundy Mill sets aside more than 100 of the 607 acres for green space, walking and biking trails and linear parks. "We're committed to keeping as much green space in Mundy Mill as possible, and hope the school board will join us in preserving natural areas," Lanier says.

The school system estimates Mundy Mill will add 1,200 students to an already over-crowded student population. REL Properties plans to develop 578 townhomes, 460 apartments, 1,148 single-family residents, 687,000 sf of office space and 510,000 sf of retail, according to preliminary development plans filed with the city.

The project's size and scope is unprecedented among a 10-county Atlanta suburban area, brokers following the venture's progress say.