I was struck by that also. But it actually might be a realistic figure. I’m more than a little familiar with the challenges of hillside development. (We built a companion unit on a sloped hill.) I assume this “grading and design” included the following:

I was wondering about that.. but I have also built on a hillside, and there are two areas you get really hit, but not this bad. If you are keeping with fairly ‘standard’ construction and standard building code, these costs are severely reduced. The soils engineer was not that much of a problem for us, though we did multiple perk tests(septic in that area) and had the soils engineer out as we were drilling the holes for the perk (this way he can look at the drill tailings). The work I was dealing with was where the house was on a slope, hitting bedrock on one side at 2 feet. This meant that the whole house had to be on bedrock (foundation flex issues). We had to go down over 8 feet on the other side of the house (thankfully the backhoe with the extending boom could just reach the bedrock on that side, but it was touch and go. 9 cubic yards of concrete in one corner 8-( .).

The last kicks in (OSHA) if there are footings of a certain depth or if retaining walls are a certain height. 5 or 6 feet from top of wall to bottom of footing. If you’re building on a hillside, you have big retaining walls to secure the building pad.

Did one of those two. House was dug into hillside, slope intersected at 10 feet for almost the entire width of the house. ‘Retaining wall’ was also back wall of house for the first story.

With 3 houses on similar situations above, we didn’t hit $250k(inflation adjusted) on the total..

Considering what I read about the kids right before my post.. I wonder if the parents are the type of people who keep changing their mind on the design and layout, and try to change the grading plan when the dozers are already there and working. Great way to run up the costs.. (when building a house, got to get a plan and stick to it).