Indiana Code Title 36. Local Government § 36-9-11.1-8

Sec. 8. (a) Real property constituting the site of parking facilities may be purchased by the board without purchasing the entire air rights over the site.  In this event, a building, buildings, or other structures may be attached to the site of the parking facility if the board approves the plans and specifications and the manner in which it shall be imposed upon or around the real property.

(b) In such a case the board may enter into an agreement to provide for use by the building, buildings, or structures of such areas of the surface of the site as may be essential for the support of the building or other structures to be erected, as well as for the connection of essential public or private utilities to the building, buildings, or structures and ingress and egress for the building, buildings, or structures.  The costs of common facilities, utilities, ingress, egress, and supports may be apportioned between the parking facilities and the buildings or structures.