Key Takeaways. A turnkey business is a for-profit operation that is ready to use as-is the moment it is purchased by a new owner or proprietor. The term "turnkey" is based on the concept of only needing to turn the key to unlock the doors to begin operations, or to put the key in the ignition to drive the vehicle. Turnkey Contract with Material and Selection of Builder. Turnkey contract agreement & selection criteria. Welcome to the construction guide blog by Team Overcs, previously we discussed that if a client is planning to build their own house they need to keep the following key factors in their mind while selecting a contractor. Turnkey contract An agreement under which a builder agrees to complete a facility so that it is ready for use when delivered to the other contracting party. A contractor may agree, for example, to build a fully equipped ad operational factory under the turkey contract.