How to build taller than 5 floors

By default, The Sims 2 allow you to built up to 5 levels. This means houses like basement + 3 floors + roof or terrace. You can eliminate the basement, or built an underground floor inside basement. There is a TRICK that allow building 6 levels: put a dormer on the highest level, but this will not allow anymore stepped roofs taller than one floor.

University Expansion Pack allows to change the floor limit: press Ctrl+Shift+C when you are in Neighborhood (NOT in a lot), type sethighestallowedlevel 16 (or any number up to 255), then open any lot and you can built more levels. If the height limit was reached, just put a dormer to unlock the limit.

Cannot build walls? You reached the wall limit!

The limit is 2100 wall segments. Half height walls are NOT counted towards wall limit, BUT you cannot build them once wall limit is reached. Foundation walls and pool walls are counted towards wall limit, BUT… you can add them even over limit. SOLUTION (trick to exceed wall limit): Delete the foundation, build as many walls as you can, then rebuilt foundation and pool.