They should fix the building system for foundations...

[dr46onfusion]

Say you build a foundation that leads to a stair downward, and then tried to put a foundation touching the ground at a lower level... It will outright never let you.

The proper fix is to try to get pixel perfect positioning so you place the 2nd foundation separately and 'hope' it's close enough to count as a pathfinding for pals.

[dr46onfusion]

They also need to either change the 'ceiling' roof platform to be treated as a floor platform, or add another building piece for floors so it lines up with foundation floors.

You will notice that objects placed in between a foundation and a ceiling side by side (using a wall to let you place them) will not work because of different levels.