Unauthorised construction

An unauthorised construction (nepovolená stavba) is a building, extension or alteration made by works without a verified project (overený projekt stavby) or against it. The Building Act, Act 25/2025 Z. z. (Stavebný zákon), calls the works nepovolené stavebné práce (§ 28 ods. 1). It also uses the words nepovolená stavba in the offence provisions (§ 80 ods. 3 písm. c)). The colloquial phrase čierna stavba ("black building") does not appear in the act. This page uses the consolidated text in force from 1 November 2025 to 31 December 2026. It marks where Amendment 243/2026 Z. z. changes the rules from 1 January 2027.

What is an unauthorised construction?

The act defines the works, not the building. Building works carried out without a verified project, or in conflict with it, count as unauthorised works (§ 28 ods. 1). The inspectorate then treats the structure that results as a building made by unauthorised works (§ 74 ods. 8 písm. d)). The act does not set a minimum size for this status.

A person who carries out unauthorised works by self-help is treated as the builder-developer (stavebník). So is the person for whom a contractor carries out such works (§ 29 ods. 4).

Which works count as unauthorised?

The table shows how the act treats common cases.

Situation	Unauthorised works?	Basis
Building or extension made without a verified project	Yes	§ 28 ods. 1
Work that departs from the verified project	Yes. A planned departure that follows the extraordinary control inspection is entered in the project instead	§ 28 ods. 1, § 43 ods. 2 and 3
Work done after the decision on building intent was cancelled on review or by an administrative court	Yes	§ 28 ods. 2
Work done under the verified project before such a cancellation	No	§ 28 ods. 2
Preparatory work before construction starts	No	§ 28 ods. 2, § 41
Minor structure on a notification built without the verified project	Yes, and a separate misdemeanour	§ 28 ods. 1, § 79 ods. 2 písm. a)

Section 41 lists what counts as preparatory work. It includes fencing the site, setting up the site facilities, clearing growth and marking the building. The start of construction means the works directly connected with making the structure.

How does the 2025 act name the old terms?

People still search for the 1976 terms, and some old procedures still run. The 1976 act (Act 50/1976 Zb.) was repealed by the Spatial Planning Act 200/2022 Z. z. Its last version ran to 31 March 2025. The table maps the old names to the current ones.

Old term	Term under the 2025 act	Where to look
Čierna stavba (colloquial)	Nepovolená stavba, nepovolené stavebné práce	§ 28 ods. 1, § 80 ods. 3 písm. c)
Removal of a building made without a building permit (§ 88 ods. 1 písm. b) of Act 50/1976)	Nariadenie odstránenia stavby by the building inspectorate	§ 74 ods. 8 písm. d), § 78
Dodatočné povolenie stavby (§ 88a of Act 50/1976)	Same name, run under the old rules for buildings that qualify	§ 84 ods. 7 písm. b)
Preskúmanie spôsobilosti stavby na užívanie	Same name, run under the old rules for buildings that qualify	§ 84 ods. 7 písm. a)

The building office that had jurisdiction under the old rules runs these old procedures (§ 84 ods. 8). Removal proceedings that the office began by 31 March 2025 also continue under the old rules (§ 84 ods. 4 písm. c)).

What can the building inspectorate do?

State building supervision belongs to the building inspectorate (stavebný inšpektorát). If an inspector finds unauthorised works, the first step depends on the case. The inspector asks the owner, builder, site manager or another person concerned to bring the building into line with the verified project. The inspector sets the deadline (§ 73 ods. 1). If the works run without any verified project, the inspector asks the builder and the contractor to stop them at once (§ 73 ods. 4). If the person does not comply or continues, the inspector reports it to the inspectorate (§ 73 ods. 2 and 5).

The inspectorate orders the owner to remove a building, change or alteration made by unauthorised works (§ 74 ods. 8 písm. d)). The order sets three things (§ 78 ods. 1).

• the deadline for removal
• the conditions for removal, such as protection of neighbouring buildings, waste removal and restoring the site
• the amount of a security for the expected cost

The owner removes the work at its own cost by the deadline (§ 78 ods. 2). If the owner does not, the inspectorate enforces the order under the administrative procedure code. A contractor hired by the inspectorate does the work. The inspectorate pays the cost first and then recovers it from the owner (§ 74 ods. 9).

The inspectorate delivers the order to the owner in person and also publishes it on its notice board and website (§ 75 ods. 4). If the owner is unknown, the inspectorate removes the building at its own cost. It can recover the cost for ten years from the date the order becomes enforceable (§ 78 ods. 4). When documents are missing, the inspectorate may ask the owner for as-built documentation or a simplified building passport (pasport stavby) (§ 74 ods. 10).

If the defect puts lives at immediate risk and the building cannot be kept, the inspectorate may exceptionally give an oral order to remove it. It must tell the owner in writing within three days (§ 78 ods. 3).

Can an unauthorised building be kept?

The text in force until 31 December 2026 has no general legalisation. It keeps two old-rules routes open through the transitional provisions in § 84 ods. 7. The first is a review of fitness for use, for a building that meets the old conditions for that review. The owner must file by 31 March 2029 (§ 84 ods. 7 písm. a)). The second is a later permit (dodatočné povolenie stavby). It is for a building that does not meet the old conditions for being treated as built in line with the rules. It also does not meet the conditions for the review. The owner must file from 1 April 2025 to 31 March 2029 (§ 84 ods. 7 písm. b)).

The old conditions come from the 1976 act and this page does not list them. Under § 88a of that act the office in a removal case had to consider a review of fitness or a later permit. The office ordered removal if the owner did not file by the deadline. It also ordered removal if the documents showed a conflict with the public interest. The building office can tell you whether a particular building qualifies.

What changes on 1 January 2027?

Amendment 243/2026 Z. z. was promulgated on 7 October 2026. Its Article I changes the Building Act from 1 January 2027 (Article XV). This is not current law until that date. The amending text makes these changes:

• The dates in § 84 ods. 7 move from 31 March 2029 to 31 December 2040. The later permit under the old act applies only to a building built by 31 March 2025.
• A new § 60 ods. 4 lets the authority approve an unauthorised building afterwards in the decision on building intent, but only for listed groups. Examples are an extension to a completed simple building and a garage, shed or pool that serves it. Related outdoor works such as a fence or paved area also qualify.
• The decision approves the building as built, within the as-built documentation. It sets conditions and a deadline for finishing or adjusting it (§ 60 ods. 6). It does not create an ownership right and does not remove liability for a misdemeanour (§ 60 ods. 7).
• An unauthorised information structure cannot be approved afterwards (§ 60 ods. 5).
• Before it orders removal, the inspectorate must call the owner to show that he or she filed an application for a later permit. The deadline is at least 60 days. If the owner shows it, the removal proceedings pause until the application ends (new § 74 ods. 9).
• Filing the application does not give a right to continue the unauthorised works (new § 57 ods. 6).

What fines apply to building without a verified project?

Making a building without a verified project, or against it, is a misdemeanour (priestupok) under § 79 ods. 3 písm. a). The fine is 30 to 15 000 EUR (§ 79 ods. 6 písm. c)). The inspectorate hears the case (§ 79 ods. 8). A sole trader or a legal person that does the same pays 10 000 to 150 000 EUR (§ 80 ods. 4 písm. a)).

Ignoring a ban on continuing the works or on removing the building is also a misdemeanour (§ 79 ods. 3 písm. e)). A sole trader or a legal person that ignores a removal order pays 1 000 to 25 000 EUR (§ 80 ods. 3 písm. d)). Amendment 243/2026 changes § 79 and § 80 from 1 January 2027, so read the new text after that date.

What should a buyer check before purchasing a house?

The removal order goes to the owner of the building (§ 74 ods. 8), so an unauthorised building becomes the buyer's problem after purchase. Ask the seller for the verified project and the final inspection certificate (kolaudačné osvedčenie). The certificate states that the building is fit for its designed purpose. The as-built documentation is its attachment (§ 67 ods. 2). For an older house, ask for the decisions issued under the old rules. Legal relations created under them stay in place (§ 84 ods. 1).

Compare the floor plan and the structure with those documents. A gap between them is the first sign of an unauthorised construction. A specialist should inspect the structure before you buy, and your lawyer should check the cadastre entries.