bruttopintaala

Bruttopinta-ala, often abbreviated as BTA, is a Finnish term for the gross floor area of a building. It is defined as the sum of the floor areas of all levels of the building measured inside the outer boundary of the exterior walls. The measurement generally includes spaces that are not directly usable for occupancy, such as stairwells, corridors, mechanical rooms, and other technical spaces, and may also include enclosed balconies or other enclosed spaces depending on the applicable standard.

Bruttopinta-ala is commonly contrasted with netto- or nettopinta-ala, which refers to the usable floor area that the occupants can use for living or business activities. Net area excludes non-occupiable spaces such as walls, shafts, and some circulation areas, resulting in a smaller figure than the gross area. The precise inclusions and exclusions can vary by jurisdiction and by the standard applied in planning, construction, or taxation.

The term is used in planning documents, building permits, property descriptions, and certain energy or taxation calculations to describe the size of a building. Because measurement practices can differ, practitioners rely on local regulations or national standards to determine which spaces are included in bruttopinta-ala for a given project.

Example: a two-storey building with 120 square meters of floor area on each level would have a bruttopinta-ala of about 240 square meters, subject to the exact inclusions defined by the applicable standard and regulations. See also nettoala for the usable area concept.