486. Property in plans.

Plans and drawings prepared by architects and engineers on behalf of a client are, in the absence of special agreement, the property of the person who pays for them1. However, documents prepared in order to assist the architect or engineer to carry out his duties remain his property as they are not brought into existence on behalf of the client2. In the absence of any special agreement, the architect or engineer owns the copyright in the plans and in the design embodied in the owner's building3. Thus if an extension to an existing building is commissioned from another architect