Multi shaped cubes

I’m trying to make 3d model to represent building. I need to have feature where you can make your own building by scaling the cube somewere with the selected area. (selected area would be the dots. Also the selected are should be scaleble)
I have no clue how this would be possible or is it even
Some bad examples at pictures and the scaling would be scaler like in the picture

Screenshot 2023-11-14 104127

TransformControls maybe?