method of drawing split level houses

[lbuttery]

consider changing floor levels when the floor/ceiling of that next area is higher/lower than 75% (approx.) or so of the than the floor/ceiling of the first area.

Also consider access to the area. If the only way to get there is via rooms/halls that are definitely on the other level than that's where that room belongs also. If access is available from either level then take your choice.

Any rooms that are "above" or "below" rooms on another floor level belong on different floor level.

It's all common sense, basically.

Lew