A cellar/basement tool (underneath the floor tool on the build GUI)
This would function similarly to the roof tool, in that you can click on the ground floor, set a depth, and pick materials for the (optional?) walls and floor.
Currently, it’s quite difficult to build things into the ground and needs a bit of trickery to be done. More issues arise when you begin designing a building on top of this basement. A tool for this purpose would solve any additional issues involving scaffolding and automated ladder placement to not get workers stuck in the excavated pit.
Here’s what I’ve found is currently required to make a decent basement (as of Dev 2395):
That’s just cruel Poor hearthlings, Its not there fault they have the idle sickness! It’s 2015 at there’s not yet a medicine for poor hearthlings who capture the disease!