Change of Structure Before Completion

What is a change of structure before completion?

A change of structure before completion (zmena stavby pred dokončením) is any modification or deviation from the approved project documentation that occurs during construction, before the building receives its final completion certificate (kolaudačné rozhodnutie). This may include alterations to materials, dimensions, layout, structural systems, building services, or the intended use of spaces. Unlike a full re-permitting process, a change represents an adjustment to an already-authorized project, addressing unforeseen site conditions, refined design decisions, or technical refinements that emerge during construction.

Under the Slovak Building Act 25/2025 (effective 1 April 2025), changes are subject to formal procedures. The law distinguishes between non-substantial deviations—which may be documented during construction—and substantial changes, which require advance authorization from the building authority (stavebný úrad) before work proceeds. This framework balances regulatory oversight with practical construction reality, where minor deviations are inevitable.

Why do changes occur during construction?

Several triggers prompt design changes mid-build. Unexpected site conditions—unforeseen ground properties, existing utilities, or groundwater—may require structural or foundation modifications. Material availability issues, code updates, or newly identified compliance gaps may necessitate substitutions or refinements. Clients may request functional or aesthetic refinements once construction is underway and spatial reality becomes tangible. Contractor-identified efficiencies or cost optimizations may suggest alternative execution methods. Coordination issues between trades, once building systems interact on site, often surface technical adjustments. The author's supervision role—performed by the project architect—is specifically designed to identify and manage these changes in real time.

How do substantial and non-substantial changes differ?

The law creates two categories of deviations, each with distinct approval pathways. Non-substantial changes are minor deviations that do not alter the building's footprint, overall height, structural integrity, fire-safety performance, use category, or functionality. Examples include slight adjustments to internal finishes, repositioning non-load-bearing walls by small margins, substituting approved materials with equivalents, or minor service routing modifications. These are documented by the author (architect) in the construction record and noted in the construction log (stavebný denník). They are reviewed and formally recorded during the final inspection (kolaudácia) but need not halt work or require advance building authority sign-off.

Substantial changes alter any critical aspect: building dimensions, footprint, height, structural system, fire compartmentalization, use classification, or accessibility provisions. These require a formal authorization process. The builder must submit a request to the building authority, accompanied by updated project documentation clearly marking the proposed modifications. An extraordinary inspection (kontrola) may be ordered before work resumes. If the changes do not affect neighbors' rights, protected public interests, or environmental assessments, authorization may be expedited. If wider impacts are identified, full statutory review with relevant authorities (environmental, fire, planning) may be required.

Who approves changes and what documentation is needed?

The building authority (stavebný úrad) has final authority to approve substantial changes. Approval begins with a formal request submitted by the builder, identifying the proposed changes, their justification, and technical impact. The request must be accompanied by updated project documentation—typically revised drawings and calculations—with the modifications clearly marked and cross-referenced to the original approved plans. The architect (author) and construction supervisor (stavebný dozor) must review and certify that changes comply with applicable building codes, safety standards, and design intent.

For changes that may affect neighbors, the building authority may require consultation or binding statements from affected parties. Environmental or specialized authority statements (fire, public health, traffic) may be required if changes touch on regulated aspects. Once all documentation is received and any required reviews are completed, the building authority issues a written permission or decision. Without this formal approval, a substantial change cannot be legally incorporated into the structure, and the building cannot receive a completion certificate.

What are the consequences of unapproved changes?

Any change executed without required authorization creates legal and practical barriers to building completion. During the final site inspection (kolaudácia)—the formal process leading to the occupancy-fitness review—the building authority compares the finished work against approved documentation. Unapproved changes are flagged as non-compliance. The completion certificate will not be issued until either the change is formally authorized retroactively or the non-compliant work is removed and rebuilt to specification.

Until a completion certificate is issued, the building cannot legally be occupied or used for its intended purpose. Occupants face legal liability; building insurance may be void. Financial penalties (pokuty) and administrative sanctions may be imposed by the building authority. In severe cases—where unapproved changes compromise structural safety or violate fundamental building codes—the authority may order removal of the affected work. This remediation is costly, disruptive, and delays occupancy. Mortgage lenders and property insurers typically require a valid completion certificate before release of funds or coverage, making unauthorized changes a financial and timeline risk.

How does a change relate to the building intent decision?

The building-intent decision is the initial authorization to construct the building. It establishes the permitted use, scale, design parameters, and any conditions or requirements. A change during construction must remain within the scope of the original intent decision. If a proposed change is so fundamental that it violates a condition of the intent decision or changes the essential nature of the approved project, it may not be approvable as a simple change; instead, a new intent decision may be required. For example, changing a residential building to commercial use, or substantially expanding the footprint beyond the consented scope, would typically exceed the authority of the change procedure. Conversely, refinements that stay within the original decision's parameters—such as altering interior layout, upgrading systems, or adjusting finishes—are properly handled as changes.

What is the timeline for recording and approving changes?

Non-substantial changes can be recorded and tracked throughout construction without halting work. The author's supervision role ensures these are documented in real time. At each site visit, the architect notes deviations in the construction log. These observations create a contemporaneous record that supports the formal final inspection. Substantial changes require advance authorization before proceeding; the timeline depends on complexity. A straightforward structural or material substitution might receive approval within days. A change affecting multiple systems or requiring external authority input may take several weeks. Builders and architects typically plan ahead, submitting change requests as soon as a deviation becomes foreseeable, rather than waiting until work is half-complete.

All changes—whether minor or major—must be resolved before the final inspection (kolaudácia). At that point, the building authority conducts a comprehensive walkthrough, reviews documentation, and either approves the structure as-built or issues a list of non-conformances to be remedied. Any change not yet formally authorized will block completion certification.

How does the 2025 building act change the process?

The Slovak Building Act 25/2025 reformed the change procedure by introducing clearer categories (substantial versus non-substantial) and streamlined authorization pathways. Under the prior regime, many changes required formal proceedings, creating delays even for trivial modifications. The new law allows minor deviations to be documented and handled during construction, reducing bureaucratic friction. Substantial changes still require building authority approval, but the law permits expedited authorization if no third-party interests are affected.

The new act also clarifies the role of the extraordinary inspection (kontrola): a builder may request an inspection before executing a substantial change, allowing the authority to assess feasibility and compliance in real time, rather than discovering non-conformance only at final inspection. This proactive approach reduces rework and delays. The law strengthens the author's supervision mandate, explicitly requiring ongoing architect oversight during construction to identify and manage deviations. This reflects the reality that modern construction requires continuous design refinement and coordination, not just one-time plan approval.

What role does the architect and construction supervisor play?

The architect (author) and construction supervisor are the primary guardians of design intent and compliance during construction. The architect conducts regular site visits, reviews work quality and alignment with plans, identifies emerging deviations, and proposes or approves necessary changes. The construction supervisor (stavebný dozor) tracks daily work, maintains the construction log, coordinates trades, and flags issues to the architect and builder. When a change emerges, the architect assesses whether it is non-substantial (can proceed with documentation) or substantial (requires building authority approval). The architect prepares or reviews updated drawings, calculations, and compliance statements, then submits these to the building authority if needed.

This collaborative oversight model recognizes that no construction proceeds perfectly to plan. Regular architecture and supervisor presence allows changes to be identified early, assessed for impact, and resolved swiftly, rather than accumulating as surprises to be discovered at final inspection. This is why author supervision is considered a best practice in residential and sustainable design, especially for passive-house and technically complex projects where precision is critical to performance.