Yes. The Building Act obliges the builder to arrange design supervision by the designer while the building is being constructed, and continuous supervision in the case of reserved buildings. Alongside it, the author of the architectural work has its own entitlement to carry out author’s supervision, even where the building design is prepared by another designer. The Act does not, however, say to what extent and for what fee the supervision is carried out; that must be set out in the contract with the designer and with the architect.
An investor holding a verified building design and a selected contractor often regards the designer’s work as finished. The new Building Act (Act No. 25/2025 Coll.) takes a different view: the designer accompanies the building through to occupancy approval, and the builder is obliged to arrange its supervision. If the contract with the designer does not address supervision, the investor discovers on site either that there is no one to carry it out, or that the designer invoices it as additional work.
What the Act requires
Among the builder’s duties is to arrange, while the building is being constructed, design supervision by the designer over the construction of the building (Section 30(4)(d) of the Building Act). For a reserved building the Act requires more: the supervision must be continuous, and the designer also checks the structural safety of the ancillary load-bearing structures (Section 30(5)(c)). The designer must attend any inspection to which it is invited because of a need to change the design or to substitute construction products, and it records in the site diary any departures from the design that it finds unremedied (Section 35(7)).
The key provision on supervision also states what the designer is not liable for:
While the building is being constructed, the designer is entitled to carry out on the site supervision by the designer over the construction of the building as regards conformity of the construction work with the building design; this is without prejudice to the entitlement of the author of the architectural work to carry out supervision over the construction of the building as regards conformity of the construction work with its proposal (hereinafter ‘author’s supervision’). The designer is not liable for changes and departures from the verified building design that it has not approved and that occurred while the building was being constructed.
— Section 35(10) of Act No. 25/2025 Coll. (unofficial English translation)
The second sentence has a practical consequence for the investor. The designer is not liable for a change made on site by the contractor without its approval. Where supervision has not been agreed and no one approves the changes, the investor faced with a later defect can as a rule turn only to the contractor, and must prove to it that the defect was caused by precisely that unapproved change.
How the designer’s supervision differs from author’s supervision
Supervision by the designer monitors whether the construction follows the verified building design. Author’s supervision belongs to the author of the architectural work, typically the architect who designed the study, and monitors conformity of the building with its proposal. Both have statutory access to the site (Section 38(2)(c) and (d)) and the right to make entries in the site diary (Section 39(2)(a) and (h)). The Act on authorised architects lists author’s supervision among the services of an architect who is the author of the work (Section 4(e) of Act No. 138/1992 Coll.).
For a developer this means that the architect retains its entitlement to author’s supervision even where the building design was elaborated after the study by another designer. If the contract with the architect does not determine the extent of the author’s supervision and the fee for it, two persons with differing views of what is still in conformity with the proposal may meet on site.
What to agree in the contracts
As regards supervision by the designer, we recommend specifying in the design documentation agreement in particular:
- whether the supervision is included in the price of the design or paid separately (as a lump sum or by inspection days actually carried out),
- the minimum scope: attendance at inspections, the frequency of site visits, the period for responding to a change proposed by the contractor,
- the procedure for approving changes, ideally by an entry in the site diary, and how this connects to an extraordinary inspection under Section 43(2),
- what happens to the supervision if you terminate the contract with the designer before construction begins.
As regards the architect, the architectural study agreement should contain an agreement on whether author’s supervision is being ordered, who pays for it and how to deal with the architect’s disagreement with a change that the investor and the designer consider necessary. The licence and consent to alterations of the work are also connected with the question of copyright in design documentation.
If the contracts are already signed and supervision is missing from them, it can be added by an amendment before construction work begins. We prepare it so that it dovetails with the construction contract with the contractor and with the construction schedule.
This answer provides general information on the law as at 12 September 2026. It does not constitute legal services or replace an assessment of an individual case. The details of your situation may differ. Book a consultation to discuss them.
