Wasted space
Floor or volume you own and pay for but get little or nothing back from — an over-wide corridor, dead air above a wardrobe, an unused balcony. Invisible by habit, but quantifiable: multiply the area by your cost per carpet sq ft.
~20% of a small flat
A typical compact 1BHK hides roughly 20% of its carpet area in wasted pockets. At ₹8,000 per carpet sq ft, ~80 sq ft of waste is about ₹6.4 lakh of space you already own but don't use.