It is possible for Sims to obtain a free house in The Sims series without the use of cheats. Here's how to do it:

  1.  Select a Sim that you want to give the house to.
  2. Next, go to a house someone else already owns.
  3. Go to the house, invite the would-be residents to the house[TS1][TS2] or simply visit the lot with the Sim[TS3][TS4] and have the Sim and one of the owners perform friendly interactions with each other until the two are friends.
  4. Then, move in the selected Sim into the house.
  5. Next, move in everyone else that you want to move in to the house.
  6. (optional, only needed if you want to get rid of the original owners) Kill the owners and keep the house to yourself.