I was not able to expand the foundation by holding down the shift key as promised. It wouldn't do it correctly. I wanted a porch on the side which didn't have steps, so I followed the lessons/tips. It didn't work. I also find I don't there is no auto roof choices for a simple house. I am used to finding the one I think works best and then clicking auto roof like in TS2. I always had to turn them off in TS3 because they were on by default. I found there are many things I can't do in this game the way I could in TS2 for sure, and or even in TS3. It was annoying and frustrating for me. I'm not a great builder, never claimed to be, but there are many features from the TS2 building options and old tools I am so used to I found the new drag and drop not worth the trade off. Like placing tiles to stop at the edge of your picture there. I was unable to do many things like that in this game.
ETA: speaking of roofs stopping where you decided they should, I also had problems with trying to get one on one lot to expand to the green edge, it ended just about 1/4 inch and no matter how much I pulled it would not go all the way to the green line where it should have expanded. I just gave up on that one and bulldozed the entire house.