Yorba Linda has 1,327 people to the square mile against Fullerton's 2,416, and the difference is all yard. What is poured here is sized for the lot, and the lot sets the access, the load and the edge.
A tract house in Fullerton has a 20 foot drive and a side yard a barrow fits through. A Yorba Linda house has a 3 car garage, a 40 to 60 foot drive, and a pad beside it for the motorhome or the horse trailer, a load a 4 inch slab is not built for. The yard behind runs to a fence with a city trail beyond it, or to the top of a graded slope on the hill tracts, and a slab that ends at either has to be detailed for it. A patio poured to the edge of a slope has only fill under its outer foot.
So we pour a Yorba Linda drive and its pad 5 inches thick on 4 inches of compacted base, with number 4 steel on an 18 inch grid under the pad, because a loaded trailer is 10,000 pounds on 4 small patches. A patio near a slope is held back by the setback the California Residential Code asks for, or carried on a footing taken below the fill. And a wall that meets a trail easement is set on our side of the line after the city has marked it, because the fence is not always the boundary.