The architect, once hired by a client, is responsible for creating a design concept that both meets the requirements of that client and provides a facility suitable to the required use. The architect must meet with, and question, the client in order to ascertain all the requirements (and nuances) of the planned project.
Often the full brief is not entirely clear at the beginning: entailing a degree of risk in the design undertaking. The architect may make early proposals to the client, which may rework the very terms of the brief. The “program” (or brief) is essential to producing a project that meets all the needs of the owner. This then is a guide for the architect in creating the design concept.
Design proposal(s) are generally expected to be both imaginative and pragmatic. Depending on the place, time, finance, culture, and available crafts and technology in which the design takes place, the precise extent and nature of these expectations will vary.
Foresight is a prerequisite as designing buildings is a very complex and demanding undertaking.