18.08.2026 - Testowa
What is included in an apartment’s floor area? Rules and standards for 2026
What is an apartment’s floor area and how is it defined by law?
In everyday language, an apartment’s floor area usually refers to its usable floor area, meaning the part of the property that residents can actually use. This concept is governed primarily by two regulations: the PN-ISO 9836 standard and the Regulation of the Minister of Infrastructure on the technical requirements to be met by buildings and their location.
The usable floor area of an apartment includes all rooms intended to meet the residents’ everyday needs. These include:
- living rooms and bedrooms,
- kitchen and pantry,
- hallway, corridor and entrance hall,
- bathroom and toilet,
- walk-in wardrobe,
- enclosed verandas and porches,
- recreational rooms and art studios.
A detailed explanation of what usable floor area of an apartment means can be found in a separate article, which explains in detail how it is calculated and interpreted.
What is included in an apartment’s floor area and what is not?
The distinction between what is included in an apartment’s floor area and what is excluded has a direct impact on the price of the property, the way it is valued and the provisions of the agreement.
Included in the floor area | Not included in the floor area |
| Living rooms, bedrooms | Balconies and terraces |
| Kitchen, pantry | Loggias (under some standards) |
| Bathroom, toilet | Staircases |
| Hallway, corridor, entrance hall | Basements and fuel storage rooms |
| Walk-in wardrobe, alcove | Technical rooms |
| Enclosed verandas and porches | Area under partition walls (depending on the standard) |
It is particularly important to pay attention to balconies and terraces. Although they are attractive features of a property and can significantly increase its market value, they are not included in the usable floor area of the apartment. The same applies to loggias, although their treatment may differ depending on the standard used.
Common areas of the building are also excluded from the apartment’s floor area. Staircases, technical rooms, pram storage rooms and bicycle storage rooms are part of the common property and do not increase the floor area of an individual apartment.
How to calculate an apartment’s floor area according to the PN-ISO 9836 standard?
Calculating an apartment’s floor area involves measuring the internal lengths of the walls at floor level. The areas of all rooms forming part of the apartment are then added together. In attic apartments, specific rules apply depending on ceiling height:
- space with a height above 1.9 m is included in full,
- space with a height from 1.4 m to 1.9 m is included at 50%,
- space with a height below 1.4 m is excluded from the calculation.
These rules ensure that the floor area of an attic apartment reflects the actual usable and functional space rather than the total horizontal projection. These principles are described in detail in the PN-ISO 9836:2015 standard, which forms the basis for most residential developments in Poland.
Total floor area, usable floor area and living area – what is the difference?
In the documentation for a single development, you may encounter three different types of floor area, each covering a different scope:
- total floor area is measured along the external outline of the walls and includes walls, shafts and structural elements of the building,
- usable floor area is what is commonly understood as the apartment’s floor area, meaning the total area of rooms measured along the internal side of the walls,
- living area includes only rooms intended for permanent occupancy and excludes the kitchen, bathroom and corridors.
The price of an apartment is determined based on its usable floor area. Living area is mainly used in public statistics and when calculating housing allowances, while total floor area is used in building design documentation.
PN-ISO 9836 and PN-70/B-02365 – where do measurement differences come from?
Differences in the measured floor area of the same apartment may result from the use of different measurement standards. In Poland, two standards may be encountered, and the developer must specify in the agreement which one is being applied.
Criterion | PN-ISO 9836 | PN-70/B-02365 |
| Stage of measurement | Finished condition | Shell condition |
| Measurement height | At floor level | One metre above the floor |
| Measurement precision | 0.01 m² | 0.1 m² |
| Sloped areas included in full | Above 1.9 m | Above 2.2 m |
| Sloped areas included at 50% | From 1.4 m to 1.9 m | From 1.4 m to 2.2 m |
Measurements taken in shell condition may produce a larger result because they do not take the thickness of plaster into account. For an apartment with an area of 60 m², the difference may typically reach around one square metre, while in an attic apartment with numerous sloping ceilings it may amount to several square metres.
At a price of several thousand or even over ten thousand zlotys per square metre, this can translate into an amount comparable to the cost of finishing an entire room. It is therefore worth asking which standard is being used before signing the agreement rather than after taking possession of the property.
Apartment floor area in a development agreement
When buying an apartment on the primary market, it is worth reading the provisions concerning the usable floor area carefully. Developers are required to state the floor area according to a specified standard, but different standards may produce different measurement results. Before signing the agreement, it is therefore worth checking which method was used to calculate the usable floor area of the apartment.
A reliable developer does not avoid this issue. J.W. Construction provides buyers with post-construction measurements of the property, allowing them to compare the actual floor area with the figures stated in the agreement before ownership is transferred.
In practice, differences between standards may amount to several square metres, which at a price of several thousand zlotys per square metre can represent a significant amount. If, after taking possession of the apartment, the floor area turns out to be smaller than stated in the agreement, the buyer is entitled to an appropriate settlement with the developer.
What floor area should you choose? Ranges based on household size
Choosing the right floor area starts with the number of residents and how the apartment will be used. The ranges below correspond to some of the most common layouts on the primary market.
Apartment type | Floor area | Suitable for |
| Studio apartment | 25–35 m² | Single person, student, rental property |
| One-bedroom apartment | 40–50 m² | Couple or remote worker |
| Two-bedroom apartment | 55–70 m² | Family with one child |
| Three-bedroom apartment | 75–90 m² | Family with two or more children |
These ranges should be treated as a starting point rather than a strict rule. The layout of the rooms is what really matters, as a well-designed 55 m² apartment may be more comfortable than a poorly planned 65 m² property.
Floor area and everyday comfort
Technical requirements set the minimum parameters below which a residential unit cannot be built. According to these rules, an apartment must have a usable floor area of at least 25 m², a bedroom for one person must be at least 8 m², and a bedroom for two people must be at least 12 m². The minimum height of residential rooms is 2.5 m.
These values represent the minimum requirements, not a standard of comfort. The difference between an 8 m² and a 12 m² room may determine whether a desk can fit next to the bed, while the difference between an 18 m² and a 24 m² living room may determine whether the dining area can function independently from the seating area.
When planning a purchase, it is therefore worth looking not only at the total number of square metres, but also at the area of each individual room. Apartment floor plans provided in development materials contain this information for each property.
How to anticipate future needs?
An apartment is usually purchased for many years, while your needs may change over time. Before deciding on the floor area, consider several possible scenarios:
- switching to remote work may require a separate workspace that a kitchen table cannot replace,
- expanding the family may mean the need for an additional room of at least 8 m²,
- older children may need separate rooms, while two siblings sharing one room generally require at least 12 m²,
- caring for an elderly family member may require a room on the ground floor or a building with a lift.
An extra room may cost less than moving again after five years, once taxes, commissions, notarial costs and the expense of finishing another property are taken into account. If any of these scenarios is likely in your case, consider choosing a floor area towards the upper end of the range suitable for your current household size.
FAQ – frequently asked questions
What is not included in an apartment’s floor area?
Balconies, terraces, staircases, basements, fuel storage rooms and technical rooms are not included in the apartment’s floor area. These elements fall outside the usable floor area even if they increase the practical or market value of the property.
What is included in an apartment’s floor area?
An apartment’s floor area includes living rooms, the kitchen, pantry, hallway, corridors, bathroom, toilet, walk-in wardrobe, alcoves and enclosed verandas and porches. These are spaces used for the residents’ everyday needs.
Is the bathroom included in the apartment’s floor area?
Yes. The bathroom and toilet are included in the usable floor area of the apartment. They are fully usable rooms and are included under both the PN-ISO 9836 standard and the regulations governing the technical requirements for buildings.
What is included in the living area of an apartment?
The living area includes only rooms intended for the permanent occupancy of residents. It is a narrower concept than usable floor area, which also includes the bathroom, kitchen, corridors and other ancillary rooms.
