Plot & Building Law: 30 Questions Before Building

The plot decides more about your building project than the house type: it determines what, how large and how high you may build at all, which ancillary costs arise and whether there are expensive surprises later. These 30 compact questions lead you in a structured way through purchase, site development, development plan (Bebauungsplan), ancillary costs and contamination – so that you have checked everything important before signing (as of 2026).

For further reading: how to systematically assess a plot is shown in the guide find & assess a plot, and reading the plan specifications is covered by the guide reading a development plan. Current prices are bundled by the guide plot prices 2026.

Buying a plot: what to clarify before signing

1. How do I even find a suitable building plot?

Besides property portals, it's worth making a direct enquiry to the municipality, checking notices, estate agents and looking at building gaps in the existing area. Municipal building areas in particular are often not widely advertised. How to search in a targeted way is shown in the guide find & assess a plot.

2. What is a building gap – and is it cheaper?

A building gap (Baulücke) is an undeveloped plot within already built-up areas. It is often already developed and well connected, but can have its own pitfalls due to narrow layouts and neighbours. Details in the guide prefab house in a building gap.

3. How do building land, expected building land and raw building land differ?

Building land (Bauland) is immediately buildable, expected building land (Bauerwartungsland) can be expected to be designated as building land in future but is uncertain, and raw building land (Rohbauland) is intended but not yet developed. Only buy if the building status is secured for your project – otherwise years of waiting can threaten.

4. What must I check in the land register?

Check the owner, encumbrances in section II (rights of way, pipeline rights, residential rights) and land charges in section III. Such burdens can considerably limit the value and buildability. The notary obtains the current land register extract for you.

5. What is a building encumbrance and why is it risky?

A building encumbrance (Baulast) is a public-law obligation towards the building authority, such as a setback or access encumbrance. It is not in the land register, but in the municipality's register of building encumbrances – check it separately by all means, because building encumbrances can strongly restrict your building planning.

6. Should I choose the plot before or after the house?

Ideally in parallel: knowing the plot and its specifications first prevents you from planning a house that won't be approved there at all. Some providers arrange both together – see the guide prefab house with plot.

Site development: is the plot ready to build on?

7. What does a "developed plot" mean?

Developed means that road, water, wastewater, electricity and usually telecommunications reach the plot boundary. Only then is the plot really ready to build on. What exactly is included is explained on the page developed plot.

8. What does developing an undeveloped plot cost?

Depending on the location and the connections still missing, several tens of thousands of euros can arise – an often underestimated item. The cost types and orders of magnitude are covered by the guide developing a plot.

9. Difference between public and private site development?

Public site development brings the utilities up to the plot boundary and is billed via contributions, while private site development runs them from there to the house – the latter you pay for in any case. Both parts belong in your cost planning.

10. Do I have to pay development contributions even for an existing property?

It's possible: if roads are renewed or finally completed for the first time, contributions can still arise even for built-up plots. Ask the municipality about open or planned measures before you buy.

11. How long does site development take?

This ranges from a few weeks for individual connections to months or years when a whole building area is developed. Factor this time into your construction schedule, otherwise the house stands before the connection.

12. What else must be considered with a sloping plot?

Sloping locations often require more elaborate development, retaining walls and an adapted foundation, which increases costs – but they offer views and design scope. What matters is shown in the guide building on a sloping plot.

Development plan & building law: what may I build?

13. Where do I find the development plan?

At the municipality or the responsible building office, often also online in the geoportal. It is publicly accessible. How to understand the details is explained step by step in the guide reading a development plan.

14. What do GRZ and GFZ mean?

The site occupancy index (Grundflächenzahl, GRZ) determines what proportion of the plot may be built on, the floor space index (Geschossflächenzahl, GFZ) the total permitted floor area. Both figures limit the house size. The calculation and the building window are explained in the guide GRZ, GFZ & building window.

15. What is a building window?

The building window (Baufenster) is the area set in the plan within which the building must stand – marked by building lines or building boundaries. Even a large plot is of little use if the building window is small. Check it carefully before the purchase.

16. What else does the development plan regulate?

Besides the type and extent of use, often the roof shape and pitch, ridge height, number of storeys, facades, sometimes even materials and the orientation of the building. A bungalow or a flat roof is not permitted everywhere – which is why the plan is the basis of every house choice.

17. What applies if there is no development plan?

Then buildability depends on the surroundings: within a locality, the project must "fit in" with the existing development, while in the outer area building is strongly restricted. A preliminary building enquiry creates legal certainty in advance here.

18. What is a preliminary building enquiry?

With a preliminary building enquiry (Bauvoranfrage), you have central questions on buildability clarified with binding effect by the authority before you submit an expensive building application. This is especially worthwhile with an unclear legal situation or if you want to deviate from the development plan.

19. How do I comply with setback areas to the neighbour?

Setback areas result from the state building code and the building height. They determine how close to the plot boundary you may build and additionally constrain the usable building field. On tight plots, they are often the limiting factor.

Purchase ancillary costs: what comes on top of the plot price

20. How high is the real-estate transfer tax?

The real-estate transfer tax (Grunderwerbsteuer) varies by federal state and is roughly between 3.5 and 6.5 percent of the purchase price. It is the largest ancillary-cost item. Your federal state states the exact rate – factor it firmly into your budget.

21. What notary and land register costs arise?

For notarisation and land register entry together, around 1.5 to 2 percent of the purchase price is usual. The notary is legally required for a plot purchase and handles the transfer of ownership securely.

22. How much does an estate agent cost?

If an estate agent is involved, a commission arises that is often split between buyer and seller and amounts to a few percent of the purchase price depending on the region. Whether and how it is split is stated in the estate agent contract.

23. Do I need a soil report – and what does it cost?

A soil report (Baugrunduntersuchung) clarifies load-bearing capacity, groundwater and soil class and is strongly recommended before you set the foundation and basement. The costs are low measured against the risk of a faulty foundation.

24. What does surveying the plot cost?

For the official measurement of the finished building and, if necessary, boundary surveying, fees arise that depend on the scope. This surveying is mandatory for completion in many federal states.

Contamination & risks: what can burden the ground

25. What is legacy contamination and how do I recognise it?

Legacy contamination (Altlasten) means soil or groundwater pollution, for example from former commercial use. Indications are given by the authority's contamination register and the history of the plot. Ask specifically, because the remediation can become very expensive.

26. Who is liable for contamination after the purchase?

In principle, the new owner too can be held responsible for the removal. That's why the check before the purchase is so important – a corresponding clause in the purchase contract and a look at the register protect you.

27. What about ordnance or archaeological finds?

In some regions there is a suspicion of unexploded ordnance in the ground; an enquiry to the ordnance clearance service creates clarity. Archaeological finds can delay construction work. Both are rare, but should be clarified in advance in case of doubt.

28. Do flood or heavy-rain hazards play a role?

Yes, check flood and heavy-rain hazard maps. Plots in risk locations can bring conditions, higher insurance costs or building difficulties. This check costs nothing and saves a lot in an emergency.

29. How do pipeline and access rights affect my building project?

If a third-party pipeline runs across the plot or the neighbour must be allowed to drive over your land, this restricts buildability and often reduces the value. Such rights are in the land register – check them before the purchase.

30. What is the most important advice before buying a plot?

Sign nothing before the development plan, site-development status, land register, register of building encumbrances and possible contamination have been checked. These checks cost little and prevent the most expensive mistakes. Combine this with a realistic overall calculation in the cost calculator and obtain suitable quotes for the house.