The Sims 3: third draft of our house (Part Four) - conflicts with basement walls and top floor

Here I begin, having just placed a segment of wall in the basement that is protruding through the floor on the main level. From the beginning, I think what I had done was raise the ground, make a basement and then lower the ground again to expose the top of the basement walls. Clearly, I determined the height of the first floor inaccurately. I'm not sure I could do it all again.

Throughout this video, I am working on placing the basement walls and windows and it is conflicting with the layout of the top floor in that, anywhere the walls above and below don't line up, you can see them.

I have no idea how to proceed. I may really have to start all over.

-- Watch live at https://www.twitch.tv/strangersonearth