By John Flanagan
On small flat sites, use floors instead of Toposurface. Use floors to represent site elements on simple sites. Create a floor type for each hardscape component (roads, sidewalk, grass, soil etc). You can see different floors illustrated below.
One advantage about using floors instead of toposurface / subregions is that you can use snaps and the Align tool, making it much easier to model curbs and place other site elements.
The surface of this site is entirely created using floors.
To create your site floor simply duplicate a generic floor and give it an appropriate name. Edit the floor structure and apply the site material eg. Grass, Asphalt, Sidewalk, Patio, Soil, Tarmac.