To lower an object you click 0 until you reach your desired height. Raising objects can add some creativity to your builds, you can use this to place clutter around your kitchen counter, put some pillows on couches, and much more. This will allow you to move objects at any height you like. To raise an object up you click 9 until you reach your desired height. If you do not have the move objects cheat entered you cannot raise or lower the objects using this method.
You need to have the move objects cheat enabled for this to work. If you want some more tips and tricks on how to better at the Sims 4 I wrote an entire article on it here, I even go beyond building tips. Getting a handle on the Move Objects cheat is a great way to improve your building skills overall in the Sims 4. If you build a room without the move objects cheat, you don’t have to worry about your sims having an issue with any of the objects in the room. Sometimes moving the objects wherever you want can be problematic because sims either can use the object or it blocks sims from being able to move around the object. This will put back the restrictions on the objects. If you want to turn the move objects cheat off you enter bb.moveobjects off into the cheat bar.