Changes to a project after obtaining a building permit. What cannot be changed without an amended permit?

The construction of a house or commercial building rarely proceeds one hundred percent according to the original plan. During the construction phase, there is often a need to introduce modifications — moving a window, changing the room layout, or even enlarging a terrace. Before making any decisions, however, you should know that Polish Construction Law strictly defines the limits of permissible modifications.

Unauthorized introduction of key changes may result in a demolition order or substantial penalties. When do your ideas become a so-called “material deviation” from the approved construction design and require obtaining an amended building permit? We explain below.

Amended permit – what is a material deviation from the design?

Under the amended provisions of the Polish Construction Law (Article 36a), all modifications to an approved construction design are divided into material and non-material deviations.

If the changes you introduce are considered “material,” you automatically lose the right to continue construction under the existing permit conditions. You must suspend construction works and apply to the relevant authority (most commonly the district authority office) for a decision amending the building permit, commonly referred to as an amended permit. This requires preparation of new documentation (a replacement design).

What cannot be changed without an amended permit?

According to Polish Construction Law, the following elements may not be modified without obtaining an amended permit:

• Characteristic building parameters: You may not independently change the building footprint area, height, length, width, or number of storeys, except for a minor 2% tolerance.

• Site development plan (PZT): It is prohibited to move the building footprint on the plot, alter the layout of internal roads, or change the location of the access road, especially if such modifications increase the building’s impact area (for example, moving the building closer to a neighboring plot and violating minimum fire-safety distances).

• Intended use of the building: If the permit concerns a single-family residential building, you cannot change part of it during construction into a large car repair workshop or a retail store without completing the required formal procedures.

• Accessibility conditions for disabled persons: This mainly concerns public and multi-family buildings. Removing ramps or elevators designed for persons with disabilities constitutes a violation of the law.

• Heat source (environmental aspect): Replacing an ecological heating source (e.g., a heat pump) with a solid-fuel boiler (coal or wood), resulting in pollutant emissions not included in the original design, is treated as a material deviation.

• Conditions established by the Local Spatial Development Plan (MPZP) or Zoning Decision (WZ): Any changes causing the building to become non-compliant with the Local Spatial Development Plan or Zoning Decision (e.g., different roof pitch, altered geometry, or façade colors inconsistent with planning requirements) require an amended permit.

The 2% tolerance – an important safeguard for investors

Construction Law provides one very important exception that protects many investors (for example, in cases of surveying or construction inaccuracies). A change in the height, length, or width of a building is not considered a material deviation if:

1.     It does not exceed 2% of the dimensions specified in the original construction design.

2.     It does not increase the building’s impact area (i.e., it does not move the building closer to neighboring properties beyond the permitted minimum distance).

3.     It does not violate other technical and construction regulations.

What can be changed during construction? (Non-material deviations)

Fortunately, the regulations leave investors considerable freedom to introduce minor adjustments that improve day-to-day functionality. These are classified as non-material deviations from the design. They include, among others:

• Moving or removing partition walls: Non-load-bearing walls may generally be modified freely.

• Internal installations layout: Changing the location of plumbing pipes, electrical outlets, or ventilation systems inside the building (provided external building parameters remain unchanged).

• Construction materials: Replacing Porotherm blocks with Ytong blocks (or vice versa) is permitted, provided the new material has equal or better structural and thermal insulation parameters.

• Roofing material: Changing ceramic roof tiles to metal roofing sheets is allowed (provided the MPZP does not prohibit it and the change does not affect the roof structure).

Who decides whether a change is material?

The key person responsible for classifying modifications on the construction site is the Designer (the author of the original design or another licensed professional assuming their responsibilities).

The designer continuously evaluates proposed changes. If they determine that a modification is non-material, they make the appropriate entry in the construction logbook and add annotations (drawings and descriptions) to the approved design documentation. Only with such as-built documentation will you be able to legally notify the completion of construction and obtain occupancy approval.

Summary

Flexibility during construction is a natural need, but unauthorized construction changes involve significant legal and financial risk. If you plan to change the building footprint area, volume, distance from plot boundaries, or intended use, you must expect the need to suspend works and obtain an amended permit. For smaller adjustments — such as partition walls, materials, or interior layouts — the approval and stamp of your architect are usually sufficient. Always consult new ideas with the designer and site manager to avoid problems during the final building inspection.