If you are interested in learning more you can join the AACE (Cost Engineering Professional Association) http://www.aacei.org/
Or my "how to" technical paper “Accurate Estimates in Less Than a Minute” which uses historical project data to estimate new projects, can be found here...
The best way to estimate new projects on a conceptual basis is to use historical project data and to escalate it. IF YOU USE a good escalation index that is relevant to your industry.
I use three cost indexes and average them. Then economies of scale adjustment must be applied. All historical...
