Steph said i should suggest this to u through here.
Adding to an existing build, by breaking down a wall and adding more floor and walls, or highlight a wall and add a door or window to the already built wall.
Example 1: Lets say i have a 4x4 house built, but want to add some more room to it, so i go the the north wall of the house and tear it down and add 3 more wall to it with a floor, cover with roof or make my own roof. aka expanding the room.
Example 2: Lets say I want to add another room to the same 4x4 house, so i add a door to the existing wall then 3 more walls and foor and roof
Example 3: Lets say i want to add an upper smaller room to the 4x4 house. So i would tear out a section of the roof, add a second floor with stairs then my 4 walls and then the roof.
this would be a great addition to the building options we have