Usable floor area (UFA)

The usable floor area (UFA) is a defined area term according to DIN 277 (Floor Areas and Volumes in Building Construction) and refers to the portion of a building’s net floor area that serves its intended purpose. It must be distinguished from circulation areas (hallways, stairwells) and technical service areas (boiler rooms, elevator shafts). The NUF is particularly important in the valuation and area calculation of commercial real estate, as well as in building valuation using the asset value method.

NUF according to DIN 277 - Structure and Categories

DIN 277 divides the net floor area (NFA) of a building into three main categories:

1. Usable floor area (UFA): Areas that serve the building’s intended purpose - e.g., offices, living spaces, retail spaces, storage areas
2. Technical functional area (TFA): Areas for building services equipment - e.g., boiler rooms, transformer rooms
3. Circulation area (VF): Access areas - e.g., hallways, stairwells, elevators

The usable floor area (NUF) is further subdivided into seven usage groups (NUF 1 to NUF 7):

NUF Group	Type of Use
NUF 1	Residential and Living
NUF 2	Office Work
NUF 3	Production, Manual and Machine Work
NUF 4	Storage, Distribution, and Sales
NUF 5	Education, Instruction, and Culture
NUF 6	Healthcare and Nursing
NUF 7	Other Uses (e.g., Parking)

This classification is relevant for building design, valuations, and cost calculations in accordance with DIN 276. In mixed-use properties (e.g., commercial on the ground floor, residential on upper floors), multiple NUF groups may be present within a single building.

Difference between NUF, living area, and rentable area

These three terms are often confused in everyday use:

• NUF (DIN 277): Technical standard for building valuation and planning; includes all areas serving the intended use without WoFlV deductions
• Living area (WoFlV): Legally relevant figure for residential lease agreements; excludes basements, boiler rooms, and unfinished attic spaces; balconies and terraces are only counted proportionally
• Leasable area (gif guideline MF-G): Industry-standard calculation basis for commercial lease agreements (office, retail) - includes proportional common areas such as hallways, restrooms, and entryways

For residential properties, the WoFlV living area is the legally decisive benchmark-not the NUF. For commercial properties, there is no legally prescribed calculation standard; the gif guideline has established itself as the industry standard. In property listings that do not specify the underlying standard, the actual usable area must therefore always be critically scrutinized.

Significance of the NUF in Real Estate Valuation

In the income approach and the cost approach, accurate area measurement plays a decisive role. Incorrect or inflated area figures lead to an incorrect calculation of the rental yield and can systematically overestimate the value of a property. When conducting valuations, appraisers typically verify the owner’s area figures through their own measurements or plausibility checks.

Practical example: An office building in Nuremberg-South is listed with a usable floor area of 850 m². Upon review, it turns out that 120 m² of circulation areas (hallways, stairwells) were included, which do not count as usable floor area. The actual usable floor area is only 730 m². At a rental rate of 11 euros/m², this results in an annual income of 96,360 euros instead of 112,200 euros-a difference that, in the income approach (at a 5% capitalization rate), leads to a value difference of approximately 316,000 euros. Accurate area determination therefore has significant financial consequences.

NUF and Energy Performance Certificates

When issuing energy performance certificates under the Building Energy Act (GEG), floor area measurements are also used-though according to the specific calculation rules of DIN 4701 and DIN 18599. The “energy reference area” used there does not necessarily correspond to the NUF according to DIN 277. Owners who have an energy performance certificate issued should ensure that the underlying area is correct-errors here can result in an energy class that is too low or too high.

Practical Tip for Property Owners in Nuremberg and Franconia

In the Nuremberg metropolitan region, we regularly see varying area specifications in property listings for commercial real estate-sometimes based on DIN 277, sometimes on the gif guideline, and sometimes without a clear indication of the standard. We make sure to always clearly state in our listings which standard the area is based on. We recommend that prospective buyers, in case of doubt, commission an independent area measurement before the purchase price is finalized.

For residential properties, we ensure that we always report the living area in accordance with the WoFlV-not the DIN 277 usable area, which is often larger and can lead to disputes during rent increases or purchase price negotiations. For older properties from the 1960s to the 1980s, existing area specifications are often calculated according to outdated standards-a new measurement is particularly recommended in these cases.

Frequently Asked Questions

Why is the NUF usually larger than the living area?

The NUF includes all areas designated for use without the deductions specified by the Living Area Ordinance. The Residential Area Ordinance (WoFlV), on the other hand, stipulates deductions for sloped ceilings (areas under 1 m in height are not counted at all; those under 2 m count only as half), terraces and balconies (usually 25-50% of the area is counted), as well as the exclusion of basements and storage rooms outside the apartment. The difference can range from 5-20% depending on the building.

Does the garage count toward the usable floor area (NUF)?

Yes, according to DIN 277, a garage counts as usable floor area (NUF 7 - Parking and Traffic). It is thus included in the NUF but not in the living area under the WoFlV. When calculating the return on investment, the garage rent can be calculated separately-combining it with the living area is misleading.

Which standard applies to commercial lease agreements in Nuremberg?

There is no legally prescribed standard. In practice, the gif guideline (gif MF/G for commercial properties) has established itself as the standard. Before concluding a contract, landlords and tenants should agree in writing on which standard will be used to calculate the rental area-otherwise, disputes may arise if the measurements and information in the property listing differ.

How is the NUF used to calculate rent?

For commercial properties, the net usable floor area is multiplied directly by the agreed-upon rent per square meter to determine the annual gross yield. This figure is incorporated into the income approach. Errors in the floor area specification therefore directly affect the income value and the purchase price-accuracy pays off.

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