These may vary from apartment to apartment or house to house. There are now minimum room sizes for buildings.
In previous years some builders were more generous with room sizes than others. Some people buy two apartments and have them knocked into a larger apartment then have the layout changed, this can be done with Off Plan or built apartments, and you would need to renegotiate costs with seller. Don’t forget to get a copy of the new plans and the approved changes agreed by the authorities. Compare the sizes or terraces and balconies, some may be bigger but then you may loose some internal space.