Risks and legal situations

Unauthorised building (černá stavba)

In Czech: Černá stavba

An unauthorised building (černá stavba) is a colloquial term for a building or part of one built without the required permit or contrary to it. The building office can order its removal, so check the documents before you buy.

Also called: černá stavba, illegal building, unpermitted construction, nepovolená stavba

What it means

The term černá stavba (literally a black building) does not appear in the law. In practice it means a building, extension or added storey built without a required decision of the building office (stavební úřad), or contrary to it. Typical examples are a garage, a roofed terrace or a converted loft that the documents do not mention at all.

For a buyer, the key point is that a mismatch between reality and the documents does not disappear with the sale. Dealing with it may become the new owner's task.

How it works in the Czech Republic

Under the Building Act No. 283/2021 Coll. (stavební zákon), a building constructed in breach of the rules can be ordered to be removed under § 250. The building office decides each case on its circumstances; whether and under what conditions a building can be approved retrospectively should be checked directly with the office or a lawyer.

Occupancy approval (kolaudace) is closely related. Buildings that require it under the new act may only be used on the basis of an occupancy decision (kolaudační rozhodnutí) and only for the purpose stated in it. For buildings that do not require it, the builder only notifies the office of completion. Older houses have documents under earlier rules, such as a kolaudační rozhodnutí or kolaudační souhlas.

A building being recorded in the land register (katastr nemovitostí) does not mean all its parts were approved. The register records mainly ownership; what was approved is shown in the building office's file.

Practical example

For example, a family house is advertised as 5+1, but the occupancy documents list only four rooms; the fifth was later created in the loft. The buyer asks the seller for documents for the conversion and, if there are none, has the building office file checked. Depending on the result, the buyer negotiates the next steps and the price with the seller.

What to watch out for

  • Ask for the building permit, occupancy documents and project drawings and compare them with reality.
  • Watch for extensions, garages, terraces and lived-in lofts missing from the documents.
  • Check in the building office file that everything being sold was approved.
  • State in the purchase agreement what the seller declares about building approvals.
  • Bear in mind that a mismatch may complicate the valuation for a mortgage.

Frequently asked questions

Can a černá stavba be recorded in the land register?

Yes. An entry in the land register does not prove that a building was properly approved; only the building office file shows that.

Does an unauthorised building always have to be demolished?

Not necessarily. The building office can order removal under § 250 of the Building Act, but decides each case on its circumstances; check the conditions with the office.

Where can I find out what was approved for a house?

In the file of the relevant building office. As a buyer, ask the owner to give you access to the documents.

  • Occupancy approval (kolaudace)Occupancy approval (kolaudace) is the procedure in which the building office allows a finished building to be used. Where Building Act No. 283/2021 Sb. requires it, it ends with an occupancy decision, without which the building may not be used.
  • Renovation (rekonstrukce)Renovation (rekonstrukce) means repairing or modernising a flat or house by renewing parts of it, such as wiring, plumbing, the bathroom, windows or roof. In Czech listings the word can cover anything from new floors to a full rebuild.
  • Land register (katastr nemovitostí)The land register (katastr nemovitostí) is the Czech public register of land, buildings and units and of the rights attached to them, such as ownership, mortgages and easements. It is run by ČÚZK through regional cadastral offices.
  • Property valuation (odhad nemovitosti)A property valuation (odhad nemovitosti) is an assessment of a flat, house or plot that a bank relies on when deciding on a mortgage. It is used to set the collateral value and thus how much the bank will lend.
  • Zoning plan (územní plán)A zoning plan (územní plán) is a municipality's main planning document. It sets where building is allowed, what each area may be used for and which conditions apply to development, so it is worth checking before buying land or a house.
  • Building plot (stavební pozemek)A building plot (stavební pozemek) is, under the Czech Building Act, a plot, part of a plot or a group of plots defined and designated for building. Whether you may really build on it depends mainly on the municipal zoning plan.

Sources

Laws and official pages this text is based on (in Czech).

This text is for information only and has not yet been checked by a legal or financial expert. It is not legal, tax or financial advice. Verify important details in the listed sources or with a professional.

Updated 25 October 2026

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