Economic Impact Assessment Tool

I'm about to attempt an economic impact assessment for a school site we have just finished in Beverley. The idea is that we work out how money going into the project was spent and respent, so producing a multiplied economic benefit. I'm starting by finding out who we employed and where thay worke / live, including subcontractors, and also do some analysis of materials to find out where they were purchased, or even manufactured. This is my first attempt so will probably end in disaster. If i get any good stuff out of it it may be useful to Esteem to show the "Hullness" of its Building Schools for the Future bid