Site Model Grade Tool

[Landartma]

I'm recreating yesterdays site model which got lost in cyberspace due to back up failure so be sure to check your back up settings.  I'm creating a site model using the stake tool.  I have an area which has approximately 2% grades (based on the eyeball method).  Can the grade tool be used to create Source Data for the creation of a site model?  I'm seeing it can be used once the site model is done but can it be used before?  I'm sitting here with a couple knowns...top of foundation interpolated FFE assuming 2x12 rafters and 1.5" sheething and flooring.  Maybe should add in for a sill plate but....it will be accurate enough.   I'm taking grades I shot and calculating the grades around the house in reference to the FFE with a calculator.  I'm doing the calculations from my station to individual spots where I don't know slope exactly.  If I can avoid calculator work that would save me some time.  Thoughts anyone.

 

BTW check out @jeffprince is doing with Drones and Lidar.