After 13 years of doing this, I'm being asked more and more to provide cost estimates on projects, but have no background in doing so. For designed projects I can easily calculate volumes of concrete, tonnage of steel, and then call producers for prices of Concrete Estimating Services. What do I do for new construction estimating for things that haven't been designed yet? I know of RS Means and things like that - are they good enough to generally get me in the ball park? Should I look for a 1-2 day course? If so, any suggestions?