Other given conditions are adjustable. A road, for instance, can be relocated. The conditions created by the building are especially important in reconstruction and installation. These conditions are generally dealt with on a level of detail that will not be considered here. When the functional requirements and the given conditions are clear, the designer knows what purpose the building should serve, and he can then propose the necessary requirements for the completed structure.
Functional requirements describe the building in terms of user criteria.
Performance criteria describe what is expected from the various building components. The structure can be created in several ways to fill these requirements. A conventional description gives a specified solution of the building tasks. In this case it is possible to put an upper limit for acceptable neighbor noise. In this case it is important to know what background noise there is, for instance TV and radio.