A contract where the construction company is responsible both for creating the design for the building and for constructing it for a lump sum price fixed in the contract. The contract between the client and contractor should contain a detailed desciption of the physical and technical requirements for the building. The primary advantages for the client are having a fixed price and a single contractor that is responsible for project delivery. Another important advantage is that usually the project can be completed faster because the contractor can begin implementation (purchasing materials & equipment, site mobilization, earth works, etc.) while the design is being completed. The disadvantages for the client are that usually the contractor demands a higher price for assuming cost and delivery risk and the client has less flexibility in introducing changes and managing the contractor closely.