How to Address an Unauthorised Building in the Czech Republic

'Illegal building' can refer to work without permission, work differing from permission or unauthorised use. The correct route depends on the facts and current law.

Establish facts and legal status

Collect decisions, plans, cadastral data and alteration history. A survey records reality; legal review identifies the conflict.

A passport is not approval

It may support an application but does not legalise the building.

Additional permitting

The authority considers statutory conditions, planning rules, public interests, technical requirements and affected rights.

Possible evidence

Depending on the case: project documentation, structural and fire assessments, surveys, statements and ownership documents.

Seek early advice

Extensions, structural changes, boundary issues, protected areas and use changes warrant early professional advice.

Need deliverables that remain usable

Before commissioning the work, define the purpose, survey scope, required accuracy, deliverable formats and acceptance checks in writing. DigiStav provides surveying, building records, 2D documentation, point clouds and BIM-ready outputs for buildings, infrastructure and industrial assets. The scope should always follow the intended use rather than a generic package.

This article provides general technical information. It is not a substitute for project-specific legal, surveying, engineering or professional-authorisation advice.

Verified sources and further reading

Czech Building Act No. 283/2021 Coll.: https://www.zakonyprolidi.cz/cs/2021-283 · Czech Decree No. 131/2024 Coll. on construction documentation: https://www.zakonyprolidi.cz/cs/2024-131 · Czech Act No. 330/2025 Coll. on construction and built-environment information management: https://www.zakonyprolidi.cz/cs/2025-330 · Czech BIM implementation portal and Building Data Standard: https://www.koncepcebim.cz/ · buildingSMART International – IFC and openBIM: https://www.buildingsmart.org/