A well-known Atlanta office developer is heading in a surprising direction in Alpharetta: office condos. Childress Klein Properties Inc., in a joint venture with Kirbo Property Services LLC, has purchased 13.5 acres at the intersection of North Point Parkway and Webb Bridge Road from Greenstone Properties for an undisclosed sum. The developers, in turn, are planning a 151,000-square-foot office condominium project called Preston Ridge Commons. Preston Ridge Commons is being billed as a Class A project with steel-frame construction and prices ranging from $175 to $185 per square foot, said Glenn Kolker with Childress Klein. The whole project is being developed in three 50,000-square-foot block phases (four buildings per phase), with phase one kicking off immediately, Kolker said. Kolker said the developers are hoping to attract demand for medical office users (one of Kirbo’s specialties), especially since Northside Hospital already has a presence near the new project. The move to office condominium development is a first for Childress Klein in Atlanta, which is better known for its high-rise office developments Atlanta Galleria and 999 Peachtree. Kolker said the project, while smaller, is similar to its Preston Ridge suburban office project. “It’s a similar product. But instead of leasing it, we’re selling it,” Kolker said. Tom Kirbo of Kirbo Property said the project will be a strong lure to the medical community as an investment vehicle, given that doctors have long been comfortable with the idea of owning their own space.