We have a building at the local university that has ground at one end level with transitory step between floors -1 and 0, you enter the building through the sta

We have a building at the local university that has ground at one end level with transitory step between floors -1 and 0, you enter the building through the stair well, and descend or ascend to get to a floor. I wouldn't be surprised if an architect designed a building that did this on flat ground, violating the ability to number floors relative to ground with integers.