Net living space: how do I calculate the living space?
What is included in the net living space in Switzerland – and how do I calculate the living space? What can I do if the information in the rental agreement is incorrect?
13.05.2025
iStock/T Turovska
1. Calculate the net living space: what counts towards living space in Switzerland?
The net living space is not defined in the same way everywhere in Switzerland. The housing valuation guide for Switzerland and SIA standard 416 serve as a guide.
The net living space is the accessible and usable floor space of an apartment. For the net living area, the following applies:
The rooms can be heated and are habitable all year round.
room height is at least 1.5 metres.
Internal and external walls are not taken into account. This means that rooms are measured from wall to wall. The volume of the walls isn’t counted as net living space.
Storage rooms and wall cabinets within the apartment are included.
SIA standard 416 is Swiss Society of Engineers and Architects and governs what is constituted as the main usable area. It is similar to what most people understand by the term "living space": the total area of all heated room areas. This also includes areas where there is furniture such as the bathtub or built-in wardrobes.
The basement, for example, is not part of the main usable area. Balconies and terraces are also ancillary space.
Gross living area, outside usable area, ancillary space: differences
There are various terms used when referring to living space. They refer to different things.
: net living area plus the outer walls.
Main usable area: total area of all heated room areas.
Outside usable area: balcony, terrace, outdoor parking space and/or garden. In some cases, this could also refer to a conservatory – if it is unheated.
Ancillary space: garage, basement, attic and/or craft room.
Living space in advertisements
Housing advertisements often living space. The definition of living space is often not specified. If in doubt, please contact the advertiser.
The term usable area is also used often. This number is usually larger than the living space. This is because it also includes balconies and basements, for example.
2. What is taken into consideration in the calculation of the net living space – and what isn't?
The net living space includes all habitable rooms. This includes but is not limited to the kitchen, bathroom and hallway.
Attics, cellars and hobby rooms are ancillary space. They aren’t counted as net living space.
Balconies and terraces are outdoor usable areas. They aren’t counted as net living space.
Covered balconies, loggias and conservatories count towards the net living space if they can be heated and are habitable all year round. If not, they are also counted as outdoor usable space.
There is no uniform standard for sloping ceilings. As a rule, areas with a roof at least 1.5 metres in height of the net living space.
Good to know: the sloping ceiling is partly shown on the floor plan. You can then determine whether the area is usable for you.
Areas under washbasins and toilets are included in the net living space. This is because you can use this space for residential purposes.
The space inside built-in cupboards and storage rooms (reduits) is part of the net living space.
3. How do I calculate the living space?
Would you like to calculate the size of your apartment in square metres? Add together the floor area of all heated and habitable rooms. The walls aren't counted as living space.
You can calculate the area of the rooms using a tape measure or a folding rule. Multiply the length of the room times the width of the room to calculate the number of square metres of the room. In rooms with sloping ceilings, only the floor area under ceilings with a height of 1.5 metres and above is counted.
Comparis tip: you can now also measure rooms using smartphone apps. To this end, search for tape measure apps in the app store. However, the measurements are often inaccurate, so they are only a starting point.
The exact net living space of the apartment is important. This is because it is used as the basis for further calculations. This includes, for example, the rental price per square metre or calculating ancillary costs. Therefore, make sure that the information provided in the rental agreement matches the actual size of the apartment.
4. What can I do if the apartment is smaller than stated in the rental agreement?
Property owners measure living space using various methods. As a result, the value in the lease agreement may be higher than the net living space according to WBS and SIA.
Comparis tip: if possible, ask about the method used to calculate the living space during the viewing.
There is no legal limit to how big the difference can be. Put simply, would you not have signed the rental agreement if you were made aware of the real size (according to WBS/SIA)? If so, the difference is too big. This is regarded as a defect in the rental property. You can then withdraw from the contract or rent reduction
Important: due to the different methods, you usually have to tolerate deviations of up to ten percent in accordance with the applicable case law
Would you like to move into a bigger apartment? You can find thousands of listings on the Comparis property marketplace.
This article was first published on 01.09.2010
