Hey Sims3lover. I will admit up front I am no expert and my experience with friezes (
placefriezes on/off) consists of one house built with the cheat (check it out in my sig.) I will share with you what I learned.
First, you cannot have two different heights connected to one another. Whether it's foundation next to a wall, a frieze next to a foundation or a wall, it can't be done. You need one square of space in between for correction - that's where the slanted walls come from. And to connect walls of different heights, you need to use the
constrainfloorelevation true/false cheat.
Second, the frieze is available after you turn that cheat on and it is the foundation tool that you use for it. To me it seems to be about 1/3 the height of a regular wall, but I haven't tried stacking friezes to check this. What I do know it that a frieze is taller than a foundation (1/4 the height of a wall) but not quite 1/2 the height of a wall.
Third, a frieze cannot be placed on the ground, or on flooring on the ground; the game tells me it can't be built on the ground floor, it needs to be built on top of existing walls or foundation.
Please allow me some time to take and post pictures to illustrate my points. I will be back here asap.
EDIT March 21: Here's the pictures with a play-by-play of what I did.
First, I'll attach a wall to a foundation (used to attach garages to houses built on a foundation.)
In the cheat box, enter (constrainfloorelevation false) -without the brackets. Then, using the wall tool, connect your wall to the foundation. Another method is to turn the constrain cheat to false before building the walls and simply starting from the attachment point. Both methods will result in this:
Now head into Terrain Tools and select the Level Terrain tool. Click on the foundation/floor to level it back to it's original position (green highlighted square in the above picture). The walls will need to remain their original height if you want to insert functional doors or windows. I choose to lower the walls even with the foundation. This is great for sunken living rooms! To do this, with the Level Terrain tool, click and drag from the foundation floor (the green highlight shows you the area affected).
Now you have this:
Enter the constrain cheat as true to turn it off. Just to illustrate, you can add more foundation adjacent to the lowered walls.
And everything can be covered with floor tile because it is all the same height.
To place a frieze on top of existing walls or foundation be sure your constrain cheat is set to true and enter (placefriezes on) -without the brackets- into the cheat box. Next, select the foundation tool and place your frieze by clicking and dragging, just like placing a foundation. Be sure you're on the correct story level, up one level from the ground in my example.
This is to illustrate the versatility of the stairs tool from foundations and friezes.
Then, I attach walls to the frieze on top of the foundation. Turn the placefriezes cheat off and enter (constrainfloorelevation false) -without the brackets- and build your walls attached to the frieze.
Flatten the floor back using the Level Terrain tool and turn the constrain cheat back to true.
More stairs!
EDIT March 22: Picture added as per Joria's request. The mint green coloured "walls" denote what is called the frieze. It is taller than a foundation but shorter than a regular wall.
