NVM brokers are obliged to measure the number of square meters of a house according to a sector-wide agreed measurement instruction. This instruction describes exactly what is or is not counted as the usable area of a house or apartment. A distinction is made between four spaces:
a) Living space, such as living room and bedrooms, toilet, hallway and meter cupboard.
b) Other indoor space, such as attached garage and attic with loft ladder.
c) Building-related outdoor space, such as balcony and loggia.
d) External storage space, such as separate shed and separate garage.
A point of attention in determining the usable area is, for example, that the height only will be measured if it is at least 1.5 meters. The outer walls are not measured, the inner walls are. Niches smaller than 0.5 m2 are ignored.