Building missing from the land register, unpermitted building and retrospective permit

A plot may have a building that the cadastral map does not show: an extension, a garage, a workshop or a garden house. Two cases should be told apart. The building may be properly permitted and the owner simply never had it recorded in the land register. Or it was built without a permit or contrary to it; then the document on the building's use that the land register requires is usually missing, and the building must first be dealt with by the building authority.

What the land register records

• The land register contains data on buildings with a descriptive or registration number and on other buildings that are the main structure on a plot (Sections 3 and 4 of the Cadastral Act No. 256/2013 Coll.). A building means an above-ground structure fixed to the ground by a solid foundation and mostly enclosed by external walls and a roof (Section 2(l)).
• Minor structures are not recorded. Under the Cadastral Act this is a single-storey structure of up to 16 m² footprint and 4.5 m height that is ancillary to the main building; a garage is never a minor structure (Section 2(m)).
• Recording a new building requires a document on how the building is used and a survey plan (Section 30). The owner must report changes to the cadastral office within 30 days (Section 37(1)(d)); failing to do so is an offence punishable by a fine (Section 57).

Note that the Building Act has its own, broader concept of a minor structure (for example, subject to conditions, a structure of up to 40 m² on the plot of a family house). It decides whether a structure needs a permit, not whether it is recorded in the land register.

Unpermitted building and retrospective permit

The building authority orders the removal of a building built without a permit or contrary to it (Section 250(1)(b) of the Building Act No. 283/2021 Coll.). The obliged person is the builder or the owner, so after a purchase also the new owner. The building can, however, be permitted retrospectively, colloquially 'legalised' (Sections 254 to 256):

• The application must be filed within 30 days of the start of the removal proceedings at the latest; the authority informs the owner of this option. An application filed earlier counts as filed when the proceedings start. Once rejected, it cannot be filed again.
• The application has the same requirements as one for a building permit and the building must meet the same conditions, including compliance with the zoning plan (Section 193).
• The building must not need an exemption from prohibitions under another law or from building requirements. An exemption only from siting requirements can be replaced by the consent of the affected neighbours. Any fine for building without a permit must be paid on time.
• For a finished building the authority may issue the occupancy decision together with the retrospective permit.

A structure that needs no permit but was built contrary to regulations is not ordered to be removed if the owner brings it into line with them (Section 254(3)). A major amendment to the Building Act was signed in September 2026, with its main part due to apply from 1 January 2027, so procedures may change further.

Why banks and insurers care

A building erected on a plot is part of it (Section 506 of the Civil Code), so it passes with the plot on sale even if it is missing from the land register. For a mortgage, however, the bank pledges and values the property according to the land register and documents: an unrecorded or unpermitted building may lower the collateral value or delay the loan until it is resolved. For home insurance, check that the policy covers extensions and outbuildings and describe them as they really are.

What to do when buying

• Compare the buildings on the plot with the cadastral map. Discrepancies that the cadastral office found in a revision and did not resolve are shown by the properties with discrepancies layer.
• Ask the seller for the permits and occupancy documents. If the documentation of a permitted building has not survived, the owner must have a building passport (pasport stavby) prepared (Section 245 of the Building Act).
• A permitted building is recorded on the owner's notification with a survey plan from a surveyor; an unpermitted one must first be dealt with by the building authority.
• Agree in the purchase contract who arranges and pays for the recording or retrospective permit.

Frequently asked questions

Must a garden shed or pergola be recorded?

A minor structure under the Cadastral Act is not recorded. A pergola without walls is usually not a building under the Cadastral Act. A garden house over 16 m² or taller than 4.5 m is no longer a minor structure for the land register. Whether a structure needed a permit is decided by the Building Act, not the land register.

Is recording a building enough to make it legal?

No. Recording does not decide whether a building is permitted: a new building can only be recorded with a document on its use, which an unpermitted building lacks. Whether the building may stay is decided by the building authority.