Ant-farm style '2D' house

You know the schoolchild project where you put soil and a small ant colony between two closely spaced glass plates. You can watch the ants mill about inside and see the tunnels they dig.

I propose a house something like that - a wall and a near-complete window one human's width apart. Of course, to get past things one has to go under or over them, so clever design is critical - the staircase needs gaps, and so on. Storage space in the back wall is permitted, provided that it consists of small cabinets.

Ideal for building as end-terrace at the end of a street, where there is a metre or so of extra space. Where retrofit to existing streets, the number zero will generally be viable on one side.