1. Open up in free build (the #2 in your home number row)
2. move the object to the selected area of your choice
3. make sure it is a safe distance from you so if it rotates or flips you won't be hit
4. Select Snap Build Mode (#1 in your home number row)
5. Let object align properly until you are satisfied with placement
6. Exit Snap Build Mode (Press the #1 on your home number row again)
Enjoy your snapped foundation/floors
(^_^)