House Model in Salome-Platform

Here is a model of a house that I designed on my own.
The plan includes a basement and ground floor.

There are several mistakes in the design:
1) The stairs are too steep. This happened because the standard stair dimensions were not taken into account when designing the house.
2) The exterior wall is slightly crooked.
3) In Salome-Platform, I had difficulty creating faces due to many unnecessary lines in the plan.
4) Water will fall from the roof into the wells because they are not protected by a cover.