So I want a basement so I have somewhere I can put all my pretty relics outside of in the middle of rooms or outside xD But I noticed a majority of the premade houses and even my cc have the brick underlayer thing (blanking on the name) Is there a way to work around it? Or even houses with basements already that came with WA?

You mean the foundation?

You can put a basement under a foundation. Move the camera to ground level to draw it. Basically the foundation functions like a (very short) extra story.

Then you just need to make a hole in the foundation (cut out part of it) over where the stairs to the basement will be, and you also need to place a short stair between floor level (on top of the foundation) to ground level, with at least one tile in between the bottom of the short stair and the top of the long stair. Or you can just put your basement stairs outside the house.

If you look at some of the tombs below buildings with foundations in WA, like the museum in France, you can see how it's done.

Yes the foundation :D

I'll try that ^-^ Thank you :D