Re: walls won't go down in build mode

I have not had a problem with walls in build mode, but I have had trouble where the finished house in play mode has locked all the walls up and locked all the floors up. The resident sims can't get into the house and keep exiting the lot.

I don't know if this is related to your problem in build mode, but I have found a solution for the above that worked for me: Visit the problem lot with a sim from a different household. Knock on the front door so the visiting sim gets invited in. This seems to force the game to unfreeze the walls and floors, and all the sims that could not get in will be busy doing their sim things inside or outside as normal. You can send the visiting sim back to its home, then go and play the problem lot and it ought to behave itself.

Hope that works for you!