Usable area in the construction design

The basic area and cubature indicator characterizing both a building and residential or usable premises is the usable area. The necessity to provide the value of this indicator at various stages of the investment results from the ordinance on the detailed scope and form of a construction project, issued on the basis of delegation from the Construction Law Act. This regulation referred to PN-ISO 9836: 2015 as the basis for calculating the area and volume. This obliges designers and, consequently, other participants in the construction process (including developers) to adhere to the terminology and rules for calculating area and cubature indices set out in this standard. This regulation is not fully respected in the regulation under discussion. The identified inconsistencies are listed in the article.