Usable area of independent homes

The total floor area of all indoor usable spaces of which the highest point is at least 1.5 metres.
Usable spaces can be divided into the ‘living area’ and ‘other indoor spaces’.
The ‘living area’ includes all spaces higher than 2 metres which in terms of physical structure are not only meant for storage.
The ‘other indoor spaces’ include:
- all spaces of which the highest point is between 1.5 and 2 metres;
- all spaces which are partly lower than 2 metres and partly, but not exceeding an unbroken 4,0 m2, higher than 2 metres;
- storage spaces, for instance a cellar, shed or garage;
- a storage attic inaccessible by fixed stairs but with ladders or folding staircase as its access, and/or an attic without sufficient daylight (window less than 0.5m²) or an attic that has no accessible floor.

Exact definition described in NEN 2580 (only in Dutch).