When specifying living and usable areas, you should not just omit rooms, but consider exactly what matters where. As for living space, do away with basements, laundry rooms, and boiler rooms entirely.
The attic is not included in the living area. It is also worth taking a close look at the stairs. If you only have one or two steps separating different levels, that is part of the living space. Stairs (from three steps upwards) are not part of the living area and can be deducted.
Sloped ceilings are also a special case: if the height of the room is less than 1 meter, the surface does not count as living space. From 1 to 2 meters, the area is calculated at 50%. Above 2 meters you should count them entirely as living space.
Balconies, loggias, roof gardens and terraces are each calculated as a quarter of the living area area.