Construction management as agent, or third party construction management, entails the construction manager acting as an agent of the owner, neither designing nor constructing the project.  The construction management as agent administers the construction contract throughout the planning, design and construction phases and is usually empowered to act on behalf of the owner regarding contract matters, overseeing design and construction; and transact specified business on behalf of the owner.

Under this model of construction management, the owner contracts separately with the construction manager, design professional and either a general contractor or (more frequently) various prime contractors. The construction manager has administrative relationships with the architect/engineer and general contractor or prime contractors, but a contractual relationship only with the owner. The construction manager is generally not responsible for the means or methods of construction and does not guarantee construction cost, time or quality aspects of the work.