Ik heb dit kunnen vinden via https://simsvip.com/2018/11/13/the-sims-4-new-game-patch-november-13th-2018/
"Previously, every building on a lot had to share the same foundation height. With today’s update, buildings that aren’t connected to each other can now have different foundation heights, or some may have no foundation at all!
We’ve also updated how you adjust the height your building’s foundation. Simply select any room and grab the new widget that appears in the center. By dragging it up or down you’ll find that it’s not only easier to use, but it’ll allow you to create buildings that soar to previously unattainable heights, or structures that are sunk down into the ground."
In het Nederlands:
Je kunt de hoogte van de fundering aanpassen door een kamer te selecteren en op de nieuwe widget te klikken die je in het midden te zien krijgt. Door deze widget naar boven of naar beneden te spelen, pas je de hoogte van de fundering aan.