A flat in Champel may be advertised at 95 m², valued at 112 m² and billed for charges on 88 m². None of these figures is wrong: they simply measure different things. In Geneva, four concepts coexist — living area, weighted area, PPE area and usable area — and confusing them distorts a comparison, a valuation, and sometimes a negotiation.
Four measurements, four figures for the same property
Before going into detail, here is what sets them apart.
| Measurement | What it counts | What it’s used for |
|---|---|---|
| Living area | The rooms you live in, under sufficient ceiling height | Comparing properties with each other |
| Weighted | Living area, plus annexes at a reduced coefficient | Estimating a market value |
| PPE | Private portions, the basis for the share | Allocating charges and voting rights |
| Usable | All exploitable space, including annexes | Describing a built volume |
Remember the short rule: living area is used to compare, weighted area to value, PPE area to allocate, usable area to describe.
Living area
This is the most commonly cited measurement, and the most intuitive: the total space in a home that its occupants can use on a daily basis. It directly influences the perceived value of a property, its functionality and its appeal.
What it includes
Bedrooms, the living room, the dining room, the kitchen and the bathrooms — the space where everyday life takes place.
What it excludes
Annexe areas: balconies, terraces, unconverted cellars and attics, garages. They exist, they have value, but they are not living area. This is precisely the role of the weighted area: to give them one.
Ceiling height
A space only counts if it is genuinely habitable, which depends on its height. Below 1.50 m, the area is not counted. Between 1.80 m and 2.40 m, it counts at 50%. Above 2.40 m, it counts at 100%. This rule explains why spacious attics with generous floor space carry little weight in a listing.
Weighted area
This is the least known measurement among the public and the most used by professionals. It answers a simple question: how do you compare a flat with a 10 m² balcony to a flat with no balcony, without acting as though the balcony didn’t exist — or as though it were worth as much as a living room?
The principle
Each space is counted according to a coefficient reflecting its usage value. Living area counts for 100%, annexes for a fraction. This produces a single figure that can be compared from one property to another.
The coefficients applied
- Living area: 100%
- Balconies: 50%
- Attic terraces: 30%
- Accessible cellars: 25%
- Convertible attics: 30 to 50% depending on comfort level
- Private gardens: 10%
- External walls: 0%
A worked example
A flat with 100 m² of living area, a 10 m² balcony, a 15 m² terrace, a 6 m² cellar and a 40 m² garden:
- 100 m² × 100% = 100 m²
- 10 m² × 50% = 5 m²
- 15 m² × 30% = 4.5 m²
- 6 m² × 25% = 1.5 m²
- 40 m² × 10% = 4 m²
That gives 115 m² of weighted area for 100 m² of living area. The calculation is set out in detail in our article How to calculate the weighted area.
PPE area
Specific to condominium ownership, the PPE area determines each co-owner’s share in the building. It is not used to describe a home: it is used to allocate.
The share
Expressed in thousandths, it derives from the surface of the private portions in relation to the building as a whole. It is this figure that determines the weight of your vote at the general meeting.
Its role in charges
Heating, maintenance, works: co-ownership charges are allocated according to this share. A difference of a few thousandths translates into francs every year, which explains why descriptive statements are sometimes disputed.
Usable area
The largest of the four: all exploitable space, including annexes, with no weighting applied. It is mainly found in new-build properties and technical specifications, where it serves to describe a volume rather than to value a property. A figure given in usable area is therefore always more flattering than one in living area — which is exactly why you need to know which one you are reading.
Which figure to look at, depending on your situation
You are selling
The weighted area is the one that drives your price, because it gives value to your annexes. But the listing will display the living area: that is what the buyer compares. Both figures must be consistent and documented — an unexplained discrepancy costs you in negotiation.
You are buying
Always compare living areas with each other. Then ask for the detail on the annexes: that is where the difference lies between two properties listed at the same price per square metre. Prices by municipality are almost always given in living area.
You are a co-owner
Only the PPE share matters for your charges and your vote. It appears in the descriptive statement of division, filed with the land registry.
The share is not an area — and it is what determines the bill
A fifth figure circulates for flats held in PPE, and it is the most poorly understood: thousandths. They are often mistaken for an area expressed differently. They are not an area.
The instrument establishing the condominium ownership sets out the delimitation of the units and, in shares with a common denominator, the share of the value of the land that each unit represents. A share of value, therefore, not of square metres. Two flats of identical area may carry different shares if one is an attic flat with a view and the other is on the first floor overlooking a courtyard — and that is perfectly regular.
The consequence is direct for your budget: co-owners contribute to common charges and administration costs in proportion to the value of their shares. Not pro rata to area, not in equal shares. The same text does however qualify this: if certain parts, structures or installations are of very little or no use to certain co-owners, this is taken into account in the allocation — which is why a ground-floor unit does not fund the lift on the same basis as a top-floor unit, where the regulations provide for this.
One last point, useful when a figure appears incorrect: shares can only be changed with the consent of all directly interested parties and the approval of the general meeting. However, each co-owner may request a correction if their share was set inaccurately by mistake, or has become inaccurate as a result of changes made to the building. A unit extended fifteen years ago without the thousandths being adjusted accordingly can be corrected — and this is worth checking before you buy, in the descriptive statement of division.
In practice, in Geneva
The measurements are standardised by the Chambre genevoise immobilière, which gives professionals across the canton a common basis. In practice, the same flat may be presented with different figures depending on who you are speaking to: the question to ask is never “how many square metres?” but “which area, measured how?”
This is the first point we check in a valuation, even before looking at the price. The technical terms used here are defined in our property glossary.