How to Make Your Own Apartment Building in "The Sims 2"

1). Select an empty lot on the Sims screen. This is a section of ground with no buildings on it. Depending on the town you have selected to play, these are usually around the outskirts. Click one, and select "Residential" from the pop-up box.
2). Select the "Building" button -- the bottom out of three icons, and build walls by selecting the wall button and dragging the wall along. Remember that you are making apartments, so you need to build a relatively big property.
3). Click the "Decoration" button, which is located just above the "Building" button. Use this to furnish the individual apartments -- each will need kitchen equipment, a bathroom and a bedroom, along with any other rooms you choose to give them. Remember that walls are not sound-proof, so don't place noisy rooms next to bedrooms -- your Sims won't sleep through noise.
4). Check that you have covered all the Sims' needs, even for computer-controlled Sims. They will need a fridge for hunger, a phone for social needs, a toilet for the bladder need, a shower for the hygiene need, a bed and a couch for comfort, and a television set or bookcase for fun, and something decorative -- wallpaper or pictures for the environment need.
5). Save the game. You will need to enter development codes now, to tell the game that multiple Sims will live here in different homes. These codes can cause abnormalities in the game, which is why they are not permanently active. Saving the game ensures you will not lose your apartment building should the codes fail.
6). Hold down "Ctrl" and "C" on the keyboard to load the code console. Type "changeLotZoning apartmentBase" without the quotation marks. If the code works, the code console will load again. If it failed, you will receive an error message. Check your spelling and try again.
7). Verify that the code worked by clicking the "Buy mode" button again, and click the round button in the top left corner. This will load the lots information screen, and the lot type should be listed as "Apartment Base."
8). Save the lot again, and find some Sims to move in as you would usually. The game will decide the weekly rent of the apartment, depending on the lot size.