Extent of building use

The extent of building use determines the extent to which a plot of land may be developed and the intensity of the permitted development. It is defined in the zoning plan by key figures such as the floor area ratio (FAR), the floor space index (FSI), the building volume index (BVI), and the eave height, and together with the type of building use, forms the core framework of public building law. Anyone purchasing a plot of land or planning a construction project must be familiar with these key figures in order to realistically assess the actual development possibilities.

The Most Important Key Figures

The floor area ratio (FAR) indicates what percentage of the lot may be built upon. A GRZ of 0.4 means: 40% of the lot area may be used as building footprint (ancillary structures such as terraces and parking spaces are included to a limited extent-up to 0.5 of the lot area as an absolute upper limit, § 19 BauNVO).

The floor area ratio (FAR) determines the total number of square meters of floor area permitted, relative to the size of the property. An FAR of 1.2 on a 500 m² property allows for a maximum of 600 m² of floor area-distributed across any number of stories, provided that the eave or ridge height and the GRZ do not impose limits. The building mass index (BMZ) is applied to commercial structures and describes the ratio of enclosed space to lot area. It does not provide direct information about the number of stories or story height, but rather about the total volume.

Calculation and Planning Relevance

The GRZ and GFZ determine the permissible number of full stories, which, together with the eave height and ridge height, limit the maximum building height. In property valuation, the degree of building utilization is decisive: A property with a high floor area ratio (e.g., 1.2 in an urban location) has significantly higher development potential than a comparably sized property with a floor area ratio of 0.4 in a rural area.

For investors and developers, the usability of a property is often more important than its raw size. The ratio of the actually utilized floor area ratio to the maximum permitted floor area ratio-the so-called utilization rate-determines whether a property still offers development potential. Properties with untapped potential can be attractive for expansions or infill development.

Exceptions and Exemptions

The zoning plan sets the rules-but not every situation is clearly regulated therein. In unplanned inner areas (§ 34 BauGB), the extent of building use is determined by the immediate surroundings (principle of integration). This means that a new building must fit in with the scale and character of the existing development. Exemptions from regulations are possible if the basic principles of the plan are not affected. However, such exemption procedures are time-consuming and uncertain; we recommend always clarifying buildability with the relevant building authority in advance.

Special regulations apply to minor ancillary structures, balconies, loggias, and terraces, which may extend beyond the floor area ratio (FAR) limit within specified boundaries (Section 19(4) of the Federal Building Code (BauNVO)). This is relevant for planning outdoor areas in new buildings and extensions.

Practical Tip for Property Owners in Nuremberg and Franconia

In Nuremberg, the floor area ratio (FAR) can vary significantly: In densely built-up downtown and Wilhelminian-style neighborhoods, values ranging from 1.0 to 2.0 are not uncommon, while in single-family home areas such as Almoshof or Kraftshof, values around 0.3-0.5 are the norm. Anyone purchasing a property or planning to add a story to an existing building should have the current zoning plan and the calculation of the already utilized floor area ratio (FAR) reviewed.

The Nuremberg City Planning Office provides information; alternatively, the City of Nuremberg’s GeoPortal, featuring a zoning plan viewer and standard land value information, is available online. We can assist you in analyzing the development potential of your property and assess whether an addition or expansion is legally and economically viable.

Frequently Asked Questions

Where can I find the zoning plan for my property in Nuremberg?

Zoning plans can be viewed through the Nuremberg City Planning Office and the online geodata portal (GeoPortal Nuremberg). Standard land values and the land use plan are also available there.

What happens if I exceed the floor area ratio (FAR)?

Exceeding the permitted floor area ratio (FAR) constitutes a formal legal violation that, in extreme cases, can lead to a demolition order. For ancillary structures (garages, terraces), there are special tolerances allowing for an FAR exceedance of up to 0.5 (Section 19 of the Federal Building Code), but these are strictly limited.

Is the building mass index (BMZ) also relevant for residential buildings?

The BMZ is primarily used in commercial zones when no floor area ratio has been set. In purely residential zones, the floor area ratio (GFZ) is the relevant indicator. Mixed-use zones may use both indicators.

How do I calculate whether there is still development potential?

Multiply the lot area by the permissible floor area ratio (FAR)-this yields the maximum permissible floor area. Compare this value with the actual existing floor area. The difference indicates the theoretical potential for expansion. Note that the plot ratio (GRZ) and height restrictions can also act as limiting factors.

What role does the eave height play alongside the plot ratio (GRZ) and floor area ratio (FAR)?

The eave height (the height of the exterior wall at the eave point, i.e., where the roof surface meets the exterior wall) limits the actual number of stories that can be built, regardless of the mathematically permissible floor area ratio (FAR). In many Nuremberg zoning plans, eave heights are set between 9 and 13 meters-which typically corresponds to three to four full stories. Even if the floor area ratio (FAR) theoretically allowed for five stories, the eave height sets the practical limit. In addition, the ridge height (the highest point of the roof) plays a role. Anyone wishing to add stories to a property or increase its density must always consider all relevant parameters-floor area ratio (FAR), floor space index (FSI), eave height, ridge height, and setback regulations-together in order to correctly estimate the actual buildable volume.

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