Building footprint (built-up area)

Under Section 13 of the Czech Building Act (Act No. 283/2021 Coll.), the built-up area of a building (zastavěná plocha stavby) is the area bounded by the outer face of the external structures of all storeys, above and below ground, projected onto a horizontal plane. Loggias and bay windows are included. For roofed structures without external walls, such as a carport, the roof projection is used. The footprints of all buildings on a plot added together give the built-up area of the plot.

What the figure is used for

• Building regulations use it to set limits. For example, minor structures that need no building permit include, subject to further conditions, a structure of up to 40 m² footprint on the plot of a family house.
• For property tax, the tax base for a building is the built-up area of its above-ground part as of 1 January.
• The RÚIAN register records the footprint of buildings with a house number.

Not to be confused with

Because it is measured to the outside of the walls, the footprint is usually larger than the floor area of a single storey, which is measured inside the rooms. It also differs from the land register's land type 'built-up area and courtyard' (zastavěná plocha a nádvoří): that describes the parcel the building stands on, and its area can differ from the footprint, for example when it includes a yard.

What to watch out for

RÚIAN records the figure from documentation of the building as built, approved by the building authority. An extension built without a permit may therefore be missing, and the figure can differ from the seller's documents. If they do not match, check the building documentation, which the owner must keep for the whole life of the building. Note also that under the Building Act the footprint includes underground storeys where they extend beyond the above-ground part, whereas property tax counts only the above-ground part.