It is not necessary to develop extremely accurate cost estimates during the project
screening activity, but the estimates must at least be realistic. A common error is
simply to obtain the cost for the main equipment item in a small project and assume
that the final cost of a project will be roughly the same amount. In reality, there are
many additional elements in the cost of any project, including foundations, piping, and
control, as well as engineering and various labor disciplines and overheads. Furthermore,
most energy efficiency projects are revamps, and these tend to be more costly
than new installations because they require working in and around existing facilities