Groen Konstancin I developed detached and terraced houses in the Groen Konstancin estate in Konstancin-Jeziorna. In materials promoting the first and second phases, including its catalogue and website, the company said residents could adapt the attic to add more than 60 square metres of living space. It advertised potential uses such as a hobby room, games room, home gym, guest room or studio, and published visualisations showing the attic as furnished living space.

In fact, the attic could not be converted into residential space. It did not meet the relevant technical requirements, including because no stairs connecting the upper floor to the attic had been designed or built. The building plans provided for two residential floors and classified the attic as non-usable space forming part of the common property.

The Polish competition authority found that the developer’s marketing misled consumers about the possibility of increasing the homes’ living area. It imposed a fine of PLN 1,176,000 on Groen Konstancin I and ordered the company to publish the decision on its website. The decision is not final and can be appealed to court.