The four constraints
The four pressures that shape every compact home — budget, light, ventilation and storage. Best used not as a checklist of problems but as four lenses, each revealing a different kind of wasted space in the same room.
Four lenses, one room
A dark, stuffy nook behind a door is a light-and-ventilation problem through two lenses, and an unclaimed-storage opportunity through a third. Switching lenses is the core skill.