Need to calculate project cost or amount of construction and building materials. Need to how how much concrete, lumber or shingles. You can find it with these sites.
http://www.ajdesigner.com/
http://www.improvenet.com/HomeOwner/projecttools/
http://www.construction-resource.com/calculators/
http://www.concrete.com/calculators.htm
http://www.building-cost.net/