"The plot is 300 sqm and the building envelope is 8 x 10m"
The living area is 160 m2. Do you have two floors plus the attic for living? What is planned for the basement, what should go in there? Is the plot roughly flat or sloped?
We have 2 full floors and a small knee wall in the attic.
A study/guest room is planned in the attic, but that could also be pushed to the back. However, it won’t save huge amounts either.
The basement is intended for a utility room, workshop, technology/heating, and party room.
The plot has a slight slope.
I also wanted a prefabricated garage. That could still be done well later, but....
Well, I will do some convincing.