How are they calculated in Croatia and why they matter?
When talking about gross building area and net usable area in residential buildings, these two terms may at first sight sound pretty self-explanatory.
However, there are some details that should be taken into account when building or buying a property in Croatia.
Especially when we know that one measure is important and frequently used when building a building, while the other one is always the subject when purchasing an apartment.
GROSS BUILDING AREA
According to Croatian law, Gross building area is the total area of all floors of a building, including the exterior walls.
Parts of the building that do not count within the gross building area are all open spaces such as balconies, terraces, loggias etc. Also, all floors or parts of the floors lower than 2 meters are not calculated within gross building area (ex: attic spaces, and parts of attic spaces lower than 2 meters).
Where do we use gross building area?
Gross building area is essential for building a building since it is one of the principal parameters defined by zoning regulations. It tells us the size of the building envelope for the specific building lot or how much there can be built.
This value is generally expressed as Ki or Kis which is defined as coefficient of usability of a building lot and it uses the following formula:
Ki or Kis = Gross building area / surface of the building lot.
It is also important to stress out that Gross building area is always present in building and use permits so it is one of the essential parameters for evaluating a building lot for the future project and for construction in general.
The method of calculation of Gross building area is defined by ordinance of the method of calculating Gross building area NN 93/17.
WHAT IS NET USABLE AREA?
Net usable area is the sum of all floor surfaces less exterior walls and room separation walls.
As opposed to Gross building area, Net usable area includes outer spaces such as balconies, terraces loggias etc.
However outer spaces do not carry the same value and they are calculated using the coefficient defined by the norm.
Therefore, all closed spaced are multiplied with 1, while loggias use the coefficient 0,75, terrace with canopy 0,5, open terraces and balconies 0,25.
Where do we use net area?
Net usable area is almost exclusively used for apartment purchase. All adds showing apartments for sale will always carry the information of net area and it’s price per square meter.
Which act defines the method of calculation of the net usable area?
Net usable area used for buying and selling apartments as explained above is defined by a norm. This norm does not have the power of law, as is the case for the gross building area but it is so widely used and recognized as the standard for determining the apartment value.
It is important to mention that banks, insurance companies as well as real estate appraisers use an Ordonance on methods of real estate valuation that slightly defers from the method in common use and described in this post.
For anyone wishing to dive deeper into the subject we always provide more extensive original version of the post written in Croatian