When you read an ad for property which is put up for sale, how can you be sure of the accuracy of the details? How do you know that the floor area specified on paper really corresponds to the space actually available? Given the need for harmonization, the Union suisse des professionnels de l'immobilier (USPI - Swiss Union of real Estate Professionals) has issued a set of standards applicable throughout Switzerland, albeit with slight cantonal differences.
Property floor areas
There are several ways of measuring the floor area of a property. This can include, at most, the floor area of the rooms, the area occupied by the interior and exterior walls as well as that of the outdoor areas (balconies, terraces). This is the gross floor area.
The percentage of this floor area actually available for the occupant, i.e. excluding interior and exterior walls and outside areas, is referred to as the net living area. It is, of course, somewhat smaller than the gross floor area.
This may be supplemented by the area taken up by a cellar, a storeroom, an indoor parking space or a garden. This ensemble is referred to as bare secondary useful floor area.
Example of calculation
Consider a property with 100 m2 gross floor area. It contains several rooms separated by interior walls and it has a balcony. Its floor area can be broken down as follows:
75 square metres are actually available for the occupant. This is the net living area.
This is supplemented by the interior walls and technical sheathing, casing and ducts (air, electricity, etc.), which cover 10 square metres. Together this corresponds to the living area (85 square metres).
This is supplemented by the exterior and party walls, which cover 8 square metres. This is the gross living area (93 square metres).
This is supplemented by the balcony, totalling 7 square metres. Together this corresponds to the gross floor area (100 square metres).
Impact on price
These details are important as the price of a property is normally calculated in square metres. And, a selling price of 7,000 Swiss francs per square metre does not return the same result if we take the gross floor area (i.e. with a price tag of 700,000 Swiss francs for an apartment totalling 100 square metres of gross floor area) or the net living area (525,000 Swiss francs for the same apartment, with a net living area of 75 square metres)!
Swiss cantons have established rules to harmonize this issue:
In the Vaud, Fribourg and Neuchâtel cantons, the determinant area is the net floor area, which comprises the net living area, plus the interior walls and outdoor areas, but not the exterior or party walls.
In the Valais canton, the gross floor area, i.e. the area which also includes exterior and party walls, is applied as the benchmark.
Consequently, care should be taken as two properties with the same surface area, where one is for sale in the Vaud canton and the other in the Valais canton, do not offer the same net living area! In this instance, the property is bigger in Vaud than in Valais.
Weighting the rooms
When calculating the floor area, certain housing components are not counted at full value because of their characteristics. A balcony, a loggia and interior walls, as such, are calculated at half their gross floor area. A terrace is calculated at a third. Mezzanines and loft spaces are only considered as floor area if the distance from floor to ceiling totals at least 1.50 metres. On the other hand, the gross floor area includes kitchen units, built-in wardrobes, fireplaces and interior staircases.