How to Properly Calculate the Surface Area of a Property for a Fair Price per Square Meter?
The calculation of a property's surface area in Switzerland can vary depending on the canton, making the task sometimes complex. To harmonize these differences, the Swiss Union of Real Estate Professionals (USPI) has established a standardized method while respecting certain cantonal specificities.

Main Calculation Methods by Canton
Not all Swiss cantons adopt the same approach to determining the surface area of a property:

• The cantons of Fribourg, Neuchâtel, and Vaud use the net sales surface, which includes the living area plus interior walls and weighted exterior surfaces. Exterior or shared walls are not considered.

• The canton of Valais adopts the gross sales surface, which additionally includes shared walls (weighted at 50%) and exterior walls.

To facilitate calculations, the USPI provides a document titled "Standard Method for Calculating Surfaces", available on its website.

Definitions of Different Surface Areas

• Net Living Area: The area inside the property's walls, meaning the space actually available for the occupant, excluding interior walls, exterior walls, and external parts of the property.

• Gross Living Area: Net living area + exterior and shared walls.

• Gross Sales Surface: Gross living area + weighted external surfaces (balconies, terraces, etc.).

In Valais, How to Calculate the Net Living Area (NLA)?

The net living area corresponds to the accessible and usable floor area inside the property, with a minimum ceiling height of 150 cm. It includes all habitable rooms such as bedrooms, the living room, kitchen, bathrooms, and hallways. Fixed elements such as fitted kitchen units, built-in wardrobes, fireplaces, and indoor staircases are also considered. However, areas with a ceiling height below 150 cm, interior walls, exterior walls, balconies, terraces, basements, and unfinished attics are not included in this calculation. Technical rooms located in the basement or cellar are also not considered. Conversely, a heated room with at least 10% natural light is included in the net living area.

• Measure the floor area of each habitable room with a ceiling height of at least 150 cm.

• Add these areas together to obtain the total net living area.

The gross living area is obtained by adding to the NLA the surfaces occupied by interior, exterior, and shared walls. In the canton of Valais, shared walls are weighted at 50%.

Calculation Example:

• Calculate the net living area.

• Measure the area occupied by interior walls.

• Measure the area of exterior walls.

• Measure the area of shared walls and apply a 50% weighting.

• Add these areas together to obtain the gross living area.

In Valais, How to Calculate the Gross Sales Surface (GSS)?
In Valais, the gross sales surface is used for real estate transactions. It includes the gross living area, plus weighted external surfaces such as balconies, terraces, and loggias. The typical weightings applied are : 50% for unheated balconies and loggias, and also 33% for terraces. Rooms located in the basement or cellar are included in the gross sales surface only if they are heated and have at least 10% natural light. Heated verandas are counted at 100% of their surface, as they are considered habitable spaces.

Calculation Example:

• Calculate the gross living area.

• Measure the area of balconies and loggias, then apply a 50% weighting.

• Measure the area of terraces and apply a 33% weighting.

• Add these weighted surfaces to the gross living area to obtain the gross sales surface.

It is important to note that these calculation methods can vary from one canton to another in Switzerland. The canton of Valais specifically uses the gross sales surface, which includes exterior and shared walls, unlike other cantons that refer to the net sales surface.

How to Calculate Your Living Area?

Before selling or valuing your property, you might be tempted to calculate its living area yourself. A laser distance meter can help save time, and by following the specific rules of your canton, you can obtain an initial estimate. However, this calculation can be more complex than it seems: different surfaces must be correctly weighted, and an error can directly impact the valuation of your property.

Don’t take risks! An incorrect estimate can lead to underpricing or, on the contrary, an overpriced listing that may slow down the sale.

At ImmoCrans, we ensure that your property is evaluated accurately, taking into account local market specificities and current standards. Our real estate experts have the tools and experience needed to determine the exact living area and maximize your property's sale price.

Compare Your Calculation with a Professional Estimate

Have you done your own calculations? Great! Now, it's time to compare them with an expert's evaluation. Contact ImmoCrans today to receive a reliable and professional estimate of your property.