Almondia – Bautipps Die Bauherrenberatung

The most important terms of building law for the purchase of land

Each property is subject to a set of building code requirements that set the parameters for all construction projects. If you are aware of these regulations in advance, you can avoid planning mistakes as early as the property purchase stage. In addition, each plot of land must also be evaluated differently in terms of construction. This article provides an overview of important building code and construction terms and associated costs.

Before buying land: Have you asked yourself all the important questions?

Building a house is always a big decision. Many factors given by the new place will determine your future everyday life. Quite sure you are already aware of these issues anyway. But have you thought about the land use plan? This is because it regulates the further development of the building land in its immediate vicinity. It shows whether major roads or industrial estates are planned. In any case, foresight is in order when choosing a building plot: you should take the necessary time to gather all the important information.

But these issues are only one side of the coin when buying land. In addition, there are a number of construction law and construction engineering aspects that specifically affect your building project. Not every plot of land that appeals to you at first glance is suitable for the planned construction project. Here it is important to inform yourself comprehensively and to ask the right questions before buying a property! In this way, the seller can be approached in an enlightened manner and all contingencies can be satisfactorily recorded in the purchase contract.

The most important questions about buying land at a glance:

  • What about the social infrastructure of the surrounding area?
  • Does the urban connection of the property meet your expectations?
  • What changes in terms of your professional activities and leisure time activities are associated with the new location?
  • Are there sources of noise in the immediate vicinity?
  • What about the future development of the surrounding area (land use plan)?

The development plan

The development plan, which is a municipal statute adopted by the municipality, has a direct impact on your building project. The development plan reflects the requirements of urban development and varies from place to place. Development plans sometimes even vary from street to street.

A distinction is made between the qualified and the simple development plan. For the developer, the qualified development plan is decisive, because it prescribes the type and extent of the building use of the property.

Of particular interest to any builder: building claims can be derived from the qualified development plan. Thus, not only can all questions concerning the permissibility of the building project be clarified here, but also a security under building law and thus a secure basis for planning can be created.

Of course, the respective development plan can be inspected at the municipalities at any time. In some cases, this is already possible on the Internet; otherwise, an appointment must be made with the municipality.

As with many legal documents, the development plan is not an easy read for the layperson. On the contrary, the abbreviations and meanings of certain colors are by no means self-evident, which is why this guide to reading a zoning plan can be very useful.

It’s in the development plan:

  • Regulations on the buildable area of the plot
  • Specifications about the division of the land
  • Specifications on the type and extent of development
  • Distance from the neighbor
    Number of floors
  • in individual cases, even provisions on aesthetic issues affecting the facade

The floor area ratio (GRZ)

If you already have a firm idea of the size of your building project, you should include this in your search for a suitable plot. Because the size of the plot determines the maximum size of your construction project. This is regulated by the floor area ratio, GRZ for short. The floor space ratio is a term from public building law (or building planning law) and can be found in the Building Use Ordinance (BauNVO). GRZ is a result of urban planning definitions that set standards on the permissible use of land. Defining a minimum amount of open space on each lot ensures a consistent development pattern and prevents excessive soil sealing. It is essential to note that all ancillary structures, such as garages, an additional carport or additional paved areas such as a terrace or driveway, are included in the calculation. Therefore, the GRZ is also important for any additions or expansions you may want to make in the future.

The GRZ defines the built-up portion to the plot area and is therefore a relative value, therefore it is given in decimal numbers: e.g. GRZ 0.4 means that 40% of the plot may be built on. Multiplying the decimal number of the GRZ by the total plot area yields the buildable plot area. However, the buildable plot area may be exceeded (in some cases by up to 50%), although it may not exceed the value of GRZ 0.8. The permissibility of such exceedances depends, for example, on ecological factors such as the nature of the soil.

An example of calculation for the buildable area of the plot:

Total plot area: 500 m², GRZ: 0.4

500 m² x 0.4 = 200 m² overbuildable property area

The floor area ratio (GFZ)

The floor area ratio, or GFZ for short, is also a value relative to the total size of the property. Thus, it also determines the degree of building use. Like the floor area ratio, the floor area ratio is a concept of public building law (or building planning law) and, like the GRZ, can be found in the development plan.

The so-called floor area refers to the gross floor area of the construction project, to which the areas of all floors of the construction are added. Accordingly, the GFZ is used to determine the number of square meters of floor area or gross floor area relative to the total size of the lot. The permissible floor area is calculated by multiplying the GFZ by the size of the plot. With the calculation performed by the GFZ, the gross floor area allowed is calculated. This is initially not accompanied by any provisions as to whether this area may be built up in height or width.

A sample calculation of the permitted floor area or gross floor area of the building project:

Total plot area: 1000 m², GFZ: 0.8

1000 m² x 0.8 = 800 m² gross floor area allowed for the building project

The subsoil investigation

The subsoil investigation excludes unpleasant surprises. This is because unfavorable soil conditions can result in insufficient load-bearing capacity of the foundation soil. The subsoil investigation thus guarantees the stability of the construction.

1. how does a subsoil investigation proceed?

During the subsoil investigation, core drilling is carried out, whereby various drill cores are taken (percussion core probing). Soil samples from all relevant soil layers (3m – 6m below the planned foundation) can provide precise information about the nature of the soil (bearing capacity and water conditions). Knowledge of the water, seepage water and groundwater conditions in the soil allows important conclusions to be drawn about the construction design and building materials and, above all, the type of waterproofing required for the components in contact with the soil. This is important not only for buildings with basements.

In problematic cases, the soil samples are re-examined in the laboratory. If the condition of the soil is poor, measures must be taken. The most costly measure, which comes into play only in very bad conditions, is the replacement of the floor.

Another method is pile driving. It measures the penetration resistance and thus the bearing capacity of the soil. A pole with a clip-shaped tip is driven into the ground and the number of hits required to penetrate 10 cm into the ground is counted.

2. costs of the subsoil investigation

The subsoil investigation should be included in the purchase contract or construction contract either as a prerequisite for a purchase or with a precise specification of the scope of the investigations. Thus, the commissioning of an executing company does not have to fall solely on the buyer of the property. Ideally, it is borne by the former owner together with the buyer. The cost of the subsoil investigation ranges from €400 to €2,500.

3. contaminated site investigation

The subsoil investigation can also be carried out in an extended form with a contaminated site investigation. This should be considered at least in certain areas where contaminated sites have been identified in the past. Incidentally, the seller is obligated to inform prospective buyers about soil contamination or contaminated sites.

The right of first refusal

The right of first refusal is a regulation registered in the land register, which should be observed when purchasing real estate. This is because the holder of the registered right of first refusal may, within a period of 8 weeks (Section 577 (2) sentence 1 of the German Civil Code (BGB)), exercise his right to purchase the property on precisely the terms on which the sale was negotiated by third parties.

For example, if the municipality is considered the holder of a right of first refusal, it can exercise its right, specifying uses, and purchase the land at your negotiated price. Holders of a right of first refusal can also be rental parties, for example.

Costs for the purchase of land at a glance

  • The broker’s commission usually amounts to 5% to 7% of the purchase price (excluding VAT).
  • Real estate transfer tax is payable on the purchase of a property. Depending on the federal state, it is between 3.5% and 5.5%.
  • Costs for preliminary building application: 50-200 € (usually not necessary with sufficient clarification through the qualified development plan)
  • Costs subsoil investigation: 400 € – up to 2500 €
  • The land survey and associated costs: up to 2600 €.
  • Costs for the inspection of the land register by the automated retrieval procedure: 50 €, plus retrieval fee per land register sheet 8 €.
  • Development costs (vary greatly): approx. 6000 € (a detailed list can be found in the overview article on development costs of a plot of land).
  • Ancillary construction costs, such as land registry and notary fees, depend on factors such as the amount of the purchase price of the property, the land charge to be registered and the type of registration/cancellation

Here you will find further information on the preliminary building application, the building plot and the soil survey, the land survey and its costs, the entry in the land register and its costs, the development of the plot and its costs and the ancillary building costs.

Calculation example:

Purchase price land: 50000 €, land charge to be registered: 40000 €

Notary fees and costs for the entries in the land register: approx. 1200 €.

A detailed list of costs in our article on land register and land charge


The described aspects of building law and building technology with regard to the plot of land should ideally already be taken into consideration when looking for suitable building land. It is worth the effort to deal with these questions: You can save cash already at the beginning of a long, financially costly construction process.

Autorin Sarah Völkl

Sarah Völkl hat Architektur studiert und ist seit Jahren das Gesicht von a better place. Mit ihren Videos ist sie bei YouTube vielen Personen schon länger bekannt. Sarah teilt Ihr Wissen jetzt auch bei den Bautipps von Almondia.

Leave a Reply

Your email address will not be published. Required fields are marked *

WordPress Cookie Plugin by Real Cookie Banner