Why is the terrain height changing when I add a basement?

I wish I knew enough about building to answer. I'm getting the same issue.

That happened to me too. It's weird :/

It happens if the terrain is lower than the basement. Simply start creating your basement at the lowest terrain point

You can adjust the height of the basement separate from the surface build, so just lower the basement. Just figured this out today.

@gmcrozier How do you lower the basement from the surface build?

@KaduMcFadu80 you use the center arrow of any basement room.

Thank you :)