The floor on the left in this pic are 30mm on a 3x3 square grid.
The floor on the right in this pic are 35mm on a 3x4 grid

I am also going to be building walls which will be 8mm thick
This is a test wall

Wondering if you were to redo the board. Or if you have already. How wide would you make the squares? 30, 35, higher, lower? and why?
Thx