Free Space in Building Mode for Wii

After playing my Sims 3 game for awhile, I decided to buy new items. When I went to do this, it said I had no available free space. I sold a few items, and it still said I had no free space. Then I tried to upgrade my house to gain space, and it told me I was violating the fire code. So I tried to sell more of my items, and still no free space. I then sold my house, along with all of my items and moved to new a building with nothing inside, and I still have no free space. So now, I have nothing, but an empty house. What can I do to create free space in my house?