Legal consequences of area discrepancies

What counts as living area and what does not?

Correct living area measurement is relevant not only for determining the selling price or rental amount but also for calculating ancillary costs and household insurance. What should be considered when calculating it?

For calculating the living area of a house or apartment, the floor area alone is not decisive; room height is also taken into account according to the Living Space Ordinance (WoFlV). Roof slopes are only partially or not at all included in the calculation of living space.

Only certain rooms are included, such as heated conservatories, terraces, heated swimming pools, loggias, and balconies. Unheated rooms are generally counted at 50%. Balconies, loggias, terraces, and roof gardens are included at 25% to 50%. Common areas such as storage rooms, attics, garages, boiler rooms, and laundry rooms are excluded.

Calculation according to WoFlV, DIN 277, or DIN 283?

In Germany, there are different methods for calculating living space: calculation according to the Living Space Ordinance (WoFlV) and calculation according to DIN standards. These calculation methods usually produce different results. Surprisingly, which method must be used is only legally prescribed for publicly subsidized housing (WoFlV). What do the common methods involve?

DIN standard 277 is a basis for evaluation and calculation of floor areas and room volumes of buildings in structural engineering. This method produces a maximum area result and is therefore advantageous for owners. For example, roof surfaces, balconies, and basement rooms are fully included in the floor area calculation. Owners of attic apartments, in particular, can report more square meters as living space on this basis than with other calculation methods.

DIN standard 283 was repealed in 1983. Nevertheless, it is still occasionally used as a basis for calculation, for example when the seller and buyer have explicitly agreed upon it. A drawback: this standard does not include regulations for garages, boiler rooms, or terraces.

Since January 1, 2004, measurements are mostly taken according to the provisions of the Living Space Ordinance (WoFlV), as courts refer to this calculation basis in disputes. Important for owners: only the part of the floor area that can be used for living is included. Roof slopes, balconies, and terraces are only partially counted. As a result, the calculated area is lower than with calculation according to DIN standard 277.

Which type of living space calculation benefits whom? Generally, a calculation according to the Living Space Ordinance is more favorable for tenants. For landlords, calculation according to DIN standard 277 is advantageous.

Legal consequences of incorrect living area calculation

For simply shaped rooms, you may be able to measure living area yourself using a laser distance meter. For irregularly shaped rooms, the calculation is more complicated and professional assistance is recommended.

Many rental or purchase contracts contain incorrect living area figures, which can have legal consequences for the owner. If the actual living area deviates by more than 10%, it constitutes a material defect. The result: buyers may withdraw from the purchase, demand a partial refund, or request a reduction in the purchase price.

It is important that the exact size is specified in the purchase contract, as only the contractual agreement counts. In short: sellers are generally liable for the accuracy of the living area figure and should ensure it is correct.