How can I modify this terrain?

Hello, I’m new at Rhino and I’m trying to model a house. I’m having trouble with the terrain. I’ve managed to sustract a part from the back side of the house, but in the front I have all this columns that lay on irregular terrain. I started working with a surface but then added thickness to use boolean difference, but now I would need to modify the surface again with Solid Points and I can’t turn them on.
Any advice on working with terrain and substracting the house volume will also help. Thank you


isolate and then explode the terrain, turn on points for the individual surfaces you need to modify, and then trim parts as needed and join, check for naked edges etc… typical modeling stuff.

solid points is usually not a good idea to use on anything else than flat surfaces, the command has to repatch the adjacent surfaces and the results can quickly get uncontrollable. it is also difficult to give you a recipe on how to proceed for this you would have to be a bit more precise and what the surface should touch, cover etc. maybe you want to take one instance at a step explain what you need and people can go through it in detail.