the effect of wall thickness and distance

What happens when you keep putting one wall further away from another wall? By moving the slider at the bottom of the window you can move the wall in the upper image. 
 

What happens when walls are increasingly more massive or increasingly thinner and when you move the wall? This can be seen in the bottom image. This can also be seen by moving the slider at the bottom of the window. Clicking the empty square to the left will show which wall thickness, distance between the walls and the ratio between these two is displayed. 
 

In both cases the intuitive “nearness” or neighbourhood (proximity) of walls changes and with it the character of the space in between. 

The art is to give spaces meaningful differences. This requires the architect to have a refined sense of proportion. This can be compared to tuning a piano or a guitar, where each string needs to be tuned to the right tone. In spatial design the plastic number is a wonderful tool for achieving the precise attunement of proportions.