Top off with top soil and grade.

That's 10%, and for reference, half of that (5%) or even less is plenty for water drainage on soil away from a house  -- but when you're talking about sidewalk, realize that max ADA cross-slope is 2%.  

You'll need to improve the soil conditions so the seed has enough nutrients.http://www.wiscnews.com/portagedailyregister/news/local/columnists/article_055ea348-84e1-59fd-8826-1221e856df12.html

Hello @Aaron Mazzrillo, I'm Sandy, a LIC.

Best, Sandy.

Hello @Joseph Smith, I'm Sandy, a LIC.

Every hospital in the nation should have mandatory training as the virus is here on US soil.

@Sandy Uhlmann Thanks for bringing that to my attention.

There are many aspects to consider when buying land like parcel legality, deed of easements, road access, fire dpt requirements, geology, soil, slope stability, drainage, sanitation, utilities, zoning, specific ordinances, specific commissions to satisfy etc; you must hire a geologist and an architect or planning expert to make sure your project is feasible before closing.

{We are doing a full-gut reno on an older unit now where the slab was poured directly on compacted soil - no drainage, no insulation, no vapour barriers.