After the walls are built, put the floor down.

You can put the walls exactly where the ground floor walls are or you can build them in other spots to allow for a balcony. Use the level up button to put you physically at the second story. Once that's done, you build the walls of the second story. You'll have to delete your roof to allow for the second story. It's best to have it a minimum of 2 wide because that allows 2 Sims to use the stairs at the same time and avoids pathing problems. Select which kind of stairs you want, whether you want the rails, and how wide you want it. Once you have enough space, go to Build Mode and click on the stairs of the house diagram. Remove all furniture, light fixtures, pictures, everything. You have to remove all objects that are in the area where you want to place the stairs. Sometimes the best place is next to a wall. They take up a lot of space, which you'll see when you try to place one. I'm not a building expert, but I've added second stories a few times.įirst of all, you need room on the ground floor to put a staircase.