The basic concept is that design decisions should take into account long-term costs, aswell as initial costs, and that the overall design solution should strike the right balancebetween these. The technique can be used at all stages in the process.At inception stage it may be used as a tool to evaluate a range of strategies for satisfyingthe demand for building space: for example, in deciding between refurbishmentof an existing facility or construction of a new one. At the briefing stage the techniquecan be used as part of the two-way dialogue between designer and client, in order to