Thursday, 5 March 2026
Legal experts are calling for an amendment to the Polish Real Estate Development Act after recent changes to the legislation led to differing interpretations of how usable floor space should be calculated.
Article 5a of the Act, which came into force on 13 February this year, was intended to clarify the method for determining the usable area of residential premises. However, according to market participants, the provision has instead resulted in uncertainty.
The wording of the article refers to the PN-ISO 9836 standard in the version applicable at the time of submitting the building permit application. A literal interpretation of this reference could allow elements such as balconies, loggias, terraces and internal staircases to be included in the usable area of a dwelling. This may affect the formally stated size of apartments and, consequently, influence pricing, ownership shares in common areas and entries in land and mortgage registers.
Shortly after the new regulation took effect, the Office of Competition and Consumer Protection (UOKiK), in a position agreed with the Ministry of Development and Technology, presented a different interpretation. The authority indicated that Article 5a should be read together with technical and construction regulations, meaning that balconies and stairs should not be counted as usable space.
While this interpretation aligns with existing market practice and is intended to protect consumers, it does not constitute a generally binding legal source and is not formally binding on courts.
Maciej Boryczko, Partner and legal advisor at GESSEL, stated that two parallel approaches have emerged: one based on a literal reading of the statute and another based on a broader systemic interpretation. He noted that differing calculation methods could lead to disputes between developers and buyers, inconsistent court rulings and increased legal risk in residential transactions.
Recent UOKiK decisions have highlighted the importance of clearly presenting the actual floor area of apartments at the pre-contract stage. Karolina Olszewska, Senior Associate at GESSEL, referred to regulatory actions in 2024 and 2025 that focused on how developers inform buyers about the inclusion of areas under non-load-bearing partition walls.
In decision RLU-1/2025, UOKiK questioned a case in which the area under removable partition walls had not been included in the usable floor area initially presented to buyers. When ownership transfer agreements were concluded, the total area was recalculated as larger, leading to additional payments.
According to the experts, the current situation requires legislative clarification. They argue that Article 5a should explicitly define the relationship between the PN-ISO standard and technical construction regulations, and clearly state which elements must be included in the calculation of usable area.
They also note that under Article 87 of the Polish Constitution, only the Constitution, statutes, ratified international agreements and regulations constitute sources of generally applicable law. Interpretative positions issued by administrative authorities do not have the same legal status.
Without further clarification, legal advisors warn that uncertainty regarding floor space calculations may continue to affect the residential market.
Source: GESSEL
