From February 13, 2026 new rules for calculating apartment floor space from developers – what you need to know

In just a few days, regulations that revolutionize how apartment floor space is calculated on the primary market will come into force. The amendment to the Developer Act, signed by the President of Poland on January 7, 2026, introduces uniform rules for calculating floor area and could mean savings of tens of thousands of PLN for buyers.

What exactly is changing?

The new Article 5a of the Act on the Protection of the Rights of Buyers of Residential Premises or Single-Family Houses and the Developer Guarantee Fund introduces a clear principle: the price of an apartment or house must be determined as the product of usable floor space and the price per square meter. Most importantly – the usable floor space must be calculated in accordance with the applicable Polish Standard PN-ISO 9836.

In practice, this means an end to the controversial practice of many developers who have been including the area occupied by partition walls in the apartment’s floor space. Buyers were paying for square meters on which walls physically stood – meters they could not actually use.

How much can you save?

Partition walls in a typical two or three-room apartment occupy between 2 and even 4 square meters of floor space. At average transaction prices in Kraków, which currently exceed 14,000 PLN per square meter, “recovering” this space means reducing the final price of the property by approximately 28,000 – 56,000 PLN.

These are not theoretical calculations. The Office of Competition and Consumer Protection has intervened in similar cases on numerous occasions. The President of UOKiK issued 6 decisions questioning developers’ practices of including the area under partition walls in the apartment’s floor space, imposing a total of over 1.6 million PLN in fines.

Who do the new regulations apply to?

The amendment applies exclusively to developer agreements concluded from the date the act enters into force, i.e., from February 13, 2026. This means that people who signed a developer agreement before this date will be settled according to the previous rules – even if the developer used a different method of measuring usable floor space.

If you are at the negotiation stage with a developer and have not yet signed a developer agreement – it is worth considering waiting to finalize the transaction until February 13. These few days could mean real savings of tens of thousands of PLN.

What to pay attention to?

Real estate market experts point out that the new regulations may raise certain interpretative doubts. The PN-ISO 9836 standard, to which the act refers, may in some cases allow for the inclusion of elements that were previously omitted in the usable floor space – such as balconies, loggias, or internal stairs.

The Polish Association of Developer Companies has already applied to the Ministry of Development and Technology for an urgent interpretation of the regulations. Until all doubts are clarified, buyers should particularly carefully check how the developer calculates the usable floor space of the property and what exactly is included in it.

How can we help?

As Eternel Real Estate Agency, we support our clients in purchasing apartments on both the secondary and primary markets. We help analyze developer offers, check documentation, and negotiate contract terms. If you are planning to buy an apartment in Kraków and need professional advice – please contact us.