It is the total surface of the fire, and represents the sum of the gross areas of all the floors of a building, above and below the ground and is measured considering the exterior of the walls that delimit, or separate the apartments.
- Balconies, balconies, private verandas and balconies;
- Accessory locations, cellars and private attics;
- The part which, on each floor, is used by the lift and forklift boxes;
- Stairs and the share of the common circulation areas of the building.
- Attics that are not habitable (that do not have legal standing for housing purposes);
- Garages located in basement, including access areas;
- Technical areas (PT, thermal power station, garbage collection compartments, etc.);
- Public galleries for public use;
- Collections in basement assigned to the various units of use of the building;
- Open terraces;
- Public outdoor galleries;
- Streets or other open spaces for public use covered by the building.