For some reason I can't place any objects inside the basement I made. When I do, I get the msg "can't place inside foundation"

I built my foundation first, then my house ontop. Then using the terrain editor, I leveled the ground inside the foundation to the exact height that a wall would be. Then I built an inner wall around the foundation to hide the slopes etc.

here is a picture to illustrate what I did.



The outer wall closest to the grass is the orginal foundation wall. The inner wall is just walls. Oddly enough I can place a stairway leading down to the basement just fine, but can't add objects in the basement.

Am I SOL? Is there any way I can make rooms and add objects in the foundation?

Have you removed the foundation within the inside walls? In my experience, that should solve your problem. Just adding the inside walls isn't enough to convince the game that the area is not a foundation.

Thank you for your help. I didn't realise I had to remove the foundation and replace the foundation with walls. I wish EA would make it so that you can build a basement using the foundation and not have to remove the foundation walls and replace it will regular walls.

I have one further question. How do I flatten the ground so that it is flush with the walls and there is no trench?

Here's what I'd try:

1) Start with the house as you have it now, with the basement floor at the correct level and the normal walls 1 tile inside of the foundation walls.

2) Move up one level, so that you are looking at the flooring on the main level, rather than at the basement flooring.

2) Using the foundation tool, hold <ctrl> and drag the foundation across the area that you want to delete, from one normal wall across to the normal wall on the opposite side of the house (ie, 1 tile inside the foundation walls). You may need to do this in sections, if the house is not a rectangle.

With any luck, the game will be willing to delete the foundations without having to remove any of the furniture, doors, windows, etc. You will probably lose the flooring on the main level, but I'm hoping that everything else will be fine.

Again, thank you for the help. I now have a functional basement.

Its too bad you have to leave 1 tile of the foundation wall. Kinda looks weird that there is the outter foundation wall and then the inner regular wall.

You would think that EA might have made it possible with the new version of the sims to build basements with foundation walls.

We finally found a way to create no-slope basements in TS2:
http://www.modthesims.info/showthread.php?t=326029

Perhaps we'll find a way to translate this technique to TS3.