apartment on foundation

[Matthew]

I've seen that some Bridgeport apartments are built on a foundation, which requires to go up the stairs to the front door of the highrise.  But can I simply make a front door on the foundation (which I raised it up) to make the foundation level be the entrance( that means, Sims need to go through the door at the foundation first, instead of using the shell door,because I want to make the shell "ground floor' the clubhouse outside.)
thank u very much!  <3