Calculating living area: Germany, Switzerland and Italy compared
Updated: 15 hours ago
When comparing properties in Germany, Switzerland and Italy, one problem quickly becomes apparent: advertised floor areas are not calculated using the same rules everywhere. A property advertised as 100 m² can therefore offer a very different amount of usable living space depending on the country.
This difference is particularly significant in Italy. German listings often quote living area calculated under the Wohnflächenverordnung, while Swiss listings commonly use net living area. In Italy, property sales are often based on the so-called saleable area (superficie commerciale). In addition to the actual living space, this can include walls and weighted portions of balconies, cellars, gardens and garages.
For a meaningful comparison, the first step is therefore to establish which definition of floor area underlies the advertised number of square metres.
1. Which floor areas are we comparing?
For the following comparison, we use three practical reference measures:
Germany: living area under the Living Area Ordinance (Wohnflächenverordnung, or WoFlV). It is not automatically mandatory for every property sale, but it is a key reference for calculating residential living area. Particularly for detached houses with cellars or extensive sloping ceilings, sellers often depart from the WoFlV and refer instead to DIN standards, which count areas more generously in the seller’s favour. Nevertheless, the WoFlV has become the generally established benchmark.
Switzerland: net living area under the federal Housing Evaluation System. Switzerland likewise has no single definition of floor area that is binding for all property listings. Net living area nevertheless provides a transparent basis for comparison. It generally includes the areas within the dwelling that can be walked on or occupied by furniture, with a ceiling height of at least 1.50 m.
Italy: saleable area (superficie commerciale) under UNI 11932:2024. This method was developed specifically to measure property area for sales purposes and is used by Italian property exchanges, among others. In addition to the main area, it includes numerous ancillary areas with different weightings. Although established, this method is not mandatory either, so calculations can vary between estate agents and valuers. Tecnoborsa’s “Codice delle Valutazioni Immobiliari”, for example, is an older but still widely used standard for calculating superficie commerciale, with some differences from UNI. Saleable area should also not be confused with other measurements, such as cadastral area.
2. How are the different areas counted?
Group | Component | Germany (Living Area Ordinance) | Switzerland (net living area) | Italy (saleable area under UNI) |
Main areas | Habitable rooms | 100% | 100% | 100% |
Living space under sloping ceilings (depending on ceiling height) | Below 1 m: 0% 1–2 m: 50% From 2 m: 100% | Below 1.5 m: 0% From 1.5 m: 100% | Average height of at least 2.4 m and minimum height of 1.5 m: 35% Minimum height of 2.4 m: 75% Minimum height of 2.7 m: 100% | |
Internal and external walls | 0% | 0% | 100% (shared walls counted at 50%) | |
Ancillary areas | Unconverted cellar | 0% | 0% | No direct access from the dwelling: 20% Direct access from the dwelling: 35% |
Converted cellar (e.g. hobby room) | Disputed. Formally included only if fully constructed and approved as living space. | If part of the dwelling and usable accordingly: 100% | With direct access from the dwelling, approval for use and a height above 2.4 m: 60% | |
Unconverted attic | 0% | 0% | No direct access from the dwelling: 20% Direct access from the dwelling, with the sloping-ceiling requirements met: 35% | |
Plant room | 0% | 0% | 15% | |
Outdoor areas | Balcony / terrace | 25% or 50% depending on quality (roof covering, orientation, etc.) | 0% | Roof terrace: 25% Balcony: 25% Terrace: 35% If covered, add 10% Up to 25 m²; beyond that, count half the applicable proportion. Without direct access from the dwelling, reduce to 1/3 |
Conservatory / veranda | Unheated: 50% Heated: 100% | If usable all year round: 100%; otherwise 0% | 70–80% | |
Courtyard | 0% | 0% | 10% | |
Garden | 0% | 0% | For an apartment: 15% For a house: 10% Without direct access: 5% See note below | |
Parking areas | Outdoor parking space | 0% | 0% | 20% |
Garage | 0% | 0% | With shared access: 50% With private access: 60% |
Note on gardens in Italy: the relevant percentage applies only up to an area equal to the main area. The next equally sized portion is counted at just 2%, and any area beyond that at only 0.5%.
3. Why is Italian saleable area often larger?
The key difference can be expressed in a simple formula:
Germany / Switzerland: usable area within the walls
Italy: gross area including walls + weighted ancillary areas
The walls alone can therefore account for a difference of several square metres. Added to this are areas that fall outside living area or net living area in Germany and Switzerland, but contribute proportionately to saleable area in Italy.
Example: the same detached house in Germany and Italy
Assume a detached house has:
100 m² of usable living space within the walls
15 m² of internal and external walls
20 m² of uncovered terrace
40 m² of unconverted cellar with direct access
20 m² of garage with private access
300 m² of garden with direct access
Calculation in Germany under the WoFlV
Walls, the unconverted cellar, the garage and the garden are not included in living area. In this example, the terrace is counted at 25%:
100 m² of living space
20 m² terrace × 25% = 5 m²
= 105 m² living area
Calculation in Italy using saleable area
In Italy, the main area is the gross area including walls. Ancillary areas are then added using their respective weightings:
115 m² of living space including walls
20 m² terrace × 35% = 7 m²
40 m² cellar × 35% = 14 m²
20 m² garage × 60% = 12 m²
Garden: 115 m² × 10% + 115 m² × 2% + 70 m² × 0.5% = 14.15 m²
= 162.15 m² saleable area
The same house is therefore listed in Germany with 105 m² of living area, but in Italy with approximately 162 m² of saleable area. In this example, the Italian figure is around 54% larger—even though the actual size and usability of the house have not changed.
4. What does this mean for buyers?
When comparing prices per square metre across Germany, Switzerland and Italy, never simply rely on the area stated in the listing.
An Italian property with 120 m² of saleable area is not directly comparable to a German property with 120 m² of living area or a Swiss property with 120 m² of net living area. The difference can be substantial, particularly where large terraces, gardens, cellars or garages are involved.
Once the area figures are comparable, use our European property price maps to put local asking prices into a wider regional context.
