Liability for Poor Construction Briefs Under Czech Civil Code

13.4.2026 | ARROWS law firm

When a construction project is not delivered as the investor envisaged, the question of liability becomes critical. A common issue is an unclear brief, which leads to disputes. Czech court decisions and the [Civil Code] clearly define the obligations of the designer, the contractor and the investor. This article will show the consequences of a poor construction brief, the allocation of risks among the parties, and will offer solutions.

The illustrative image shows an expert consulting on liability for construction defects.

The practical risk of incorrect specifications for the individual parties
What happens with incorrect specifications during construction: obligations of all parties
The role of a contract for work in preventing disputes
Final summary
FAQ: Developers and liability for construction specifications

Key takeaways

The developer bears primary responsibility for the quality of the construction specifications and for clearly defining the subject matter of the contract. Vague specifications significantly increase the risk of court disputes and cost overruns.

The designer must point out incorrect specifications from the developer that would lead to improper performance of the work or a breach of regulations. Otherwise, the designer may be liable for defects.

The contractor has a duty to point out issues with the design documentation or specifications during performance, not only after completion. Failure to comply with this duty may result in the contractor’s liability for defects.

Czech case law distinguishes between defects in the work (existing upon handover or manifested later) and incomplete works (parts not performed). Liability and time limits differ in these cases.

A well-prepared contract for work with precise scope definition, a schedule, and contractual penalties is the best prevention against disputes.

How liability is allocated between the developer, the designer, and the contractor

When anything goes wrong on a construction project, the first question is: who is responsible? The answer is not straightforward, because liability is divided among several parties and Czech law places it differently in each situation. Let’s break it down specifically.

The developer as the initiator of the construction

The developer (hereinafter the “client”) is the owner of the land and the initiator of the entire project. This means the client bears primary responsibility for ensuring that what they set out in the contract and instruct the contractor to do is formulated in a way that does not later lead to conflicts. If, for example, the client writes in a tender “build me a cake” without specifying the size, materials, number of tiers, and budget, then they cannot be surprised later when the contractor builds something different from what the client had in mind.

Czech legal practice clearly provides that the client cannot later deny responsibility for what they specified. Under Section 2594 of the Civil Code (hereinafter the “Civil Code”), if the client gives the contractor an instruction concerning the work from which it is apparent that the work would be performed in an evidently unsuitable manner, the contractor must notify the client of this.

If the contractor fails to do so, the contractor is liable for defects in the work that arose from such instruction and cannot rely on incomplete or unsuitable specifications. Conversely, the contractor cannot claim payment for additional works that arose as a result of defects in the specifications that the contractor failed to report.

However, if the client insists on performance of the work according to the instruction despite having been warned by the contractor of its unsuitability, the contractor is not liable for defects in the work arising from that instruction.

In practice, it may look like this: The client engages a designer to prepare design documentation (DD) based on the client’s verbal idea. The designer prepares DD, but it does not correspond to what the client actually wanted. The client only discovers this during construction.

In such a case, the client cannot automatically claim that the designer failed—they must first prove it by a specific deviation from the contractual specifications. If the client only told the designer orally “build a modern house” without further details, it will be very difficult later to argue that the designer breached the contract.

The designer’s role and its specifics

The designer has a particularly delicate role because they work with intangible performance—documentation and plans. If the designer receives incorrect or incomplete specifications from the developer that would lead to improper performance of the work or a breach of public-law regulations, the designer has a duty to point this out immediately and require the client to clarify the specifications.

This duty follows from the general duty of a professional to act with due care. If the designer fails to do so and it is later discovered during construction that the DD does not correspond to the investor’s actual wishes, the designer may defend themselves by showing that they clearly warned the client (developer) about defects in the specifications.

Czech courts also adhere to the view that the designer is responsible for ensuring that the DD is complete and professionally correct in terms of construction standards and the Building Act—i.e., what the designer themselves delivered. If the designer prepares DD that breaches technical standards or construction regulations (e.g., Building Act No. 283/2021 Coll., as amended), the designer is liable for this even if the client formulated the specifications vaguely.

The designer is liable for defects in the work, i.e., the design documentation. If a defect in the design documentation causes a defect in the construction itself, the designer is liable for that defect.

There may also be situations where the designer and the contractor bear joint and several liability for defects in the construction if both contributed to the defect (e.g., the designer through defective documentation and the contractor by failing to point out the defect and building according to it).

Note: This does not mean the designer is liable for the developer’s ideas that conflict with the law or professional standards. The designer is only liable for ensuring that what they themselves prepared is professionally correct and compliant with legal regulations.

If the client intentionally wants a house with wider windows without ensuring a structural engineer’s assessment, the designer must refuse to propose a solution that conflicts with structural requirements. Alternatively, the designer must clearly warn the client of the risks and request written confirmation of assumption of responsibility, provided this is not contrary to legal regulations.

Site manager and the developer’s technical supervision

Many developers believe that the site manager is their protective element on the construction site. That is a misconception. The site manager is a person professionally qualified to carry out construction works who manages the execution of the construction (under Section 152 of Act No. 283/2021 Coll., the Building Act).

Typically, the site manager is an employee of the construction company, not the developer. The site manager is responsible for proper execution of the construction, manages the construction company’s workers, makes entries in the electronic construction log, and reports to the company’s management on the progress of the construction. The site manager is not the developer’s representative.

The developer therefore needs a completely separate party—the developer’s technical supervision (previously sometimes referred to as the investor’s technical supervision or construction supervision). This is an independent professional whom the developer hires and pays.

The developer’s technical supervision monitors the construction in the developer’s interest, ensures that the construction is carried out in accordance with the DD and the contract, and immediately points out problems.

Although the developer’s technical supervision is not mandatory for private construction, arranging it is in every developer’s interest. However, for public procurement construction works and for buildings carried out by self-build, the developer’s technical supervision is mandatory.

Legally, the situation is as follows: The developer’s technical supervision is liable for their own failures in supervision. Specifically, they are liable for what they themselves “delivered,” meaning their supervision and control.

If the technical supervisor missed a defect that they should have identified with due professional care, they are liable for the damage caused by their professional negligence. This also means it is important to have a high-quality technical supervisor acting for the developer, because the absence or dysfunction of such supervision may be difficult for the developer to address later.

Contractor

The contractor is the person who physically carries out the construction. Under Section 2615 et seq. of the Czech Civil Code, the contractor is responsible for ensuring that the work corresponds to the contract. If the client or the designer provides the contractor with incorrect instructions, the contractor cannot simply wait passively.

The contractor has a duty to notify the client without undue delay of any deficiencies, and if a defect in the design prevents proper performance, the contractor must suspend the works until the situation is resolved. This duty is set out in Section 2594 of the Czech Civil Code.

However, the contractor remains responsible for the quality of performance and for compliance with construction standards regardless of whether the design documentation was defective. This is essential.

The contractor cannot claim that their construction error was caused by a defective design. They are always liable if they performed the work poorly.

The court will protect the contractor only if they prove that the defect was caused by an error in the design documentation and that they notified it in time—rather than it being due to their own negligence.

Practical risk of unclear or incorrect instructions for the parties involved

When a developer and a contractor agree on construction only orally or with very vague specifications, several specific risks arise. Let’s break them down with practical examples.

What happens if the developer changes the specifications during construction

A very common situation: The developer orders construction based on a sketch they drew themselves. During construction, the developer realizes they wanted something completely different. Now they ask: can I enforce this without paying more?

The answer according to Czech case law is: No. If the developer raises requirements during construction that are not included in the design documentation or the contract, they must pay for them.

Specifically, the developer then orders a change to the work, which must be agreed with the contractor and recorded in the electronic construction log.

If it is a major change, it must be approved by the building authority if it concerns parameters subject to a building permit or notification (under Act No. 283/2021 Coll., the Building Act). All such additional works are invoiced separately.

In practice, this leads to a dramatic increase in the original budget. The reason is simple—changes during construction are economically inefficient, and the construction company is entitled to charge mark-ups for them. In such cases, the court sides with the construction company if the original contract was clear and the developer changed things during construction.

When the developer does not have to pay for additional works

There is an exception: If, during construction, it is discovered that the design documentation contains errors that no one could have foreseen when entering into the contract and that lead to additional works, the client does not necessarily have to pay for them automatically.

In such a case, the key issue is the designer’s liability for the error, and the costs of rectification are borne by the designer, or covered by their professional liability insurance.

Typically: The designer proposes foundations in the design documentation, and during construction it is found that they are not statically adequate for the specific soil type on the plot. The developer therefore does not have to pay for strengthening the foundations—this is a defect in the design documentation and the designer is liable for it, provided the contractor duly and timely pointed out the defect.

What problems arise when it is unclear what is to be built

The most common problems that ARROWS attorneys see in practice are an unclear scope of work. The developer and the construction company disagree on what is included in the construction. For example, the developer believes that the construction price includes landscaping and greenery, while the construction company does not.

This leads to a dispute lasting many months, during which the construction is at a standstill and no one does anything. The court then decides based on how the contract was drafted, and it almost always turns out that ambiguities work against the party who drafted the contract (commonly the construction company, but this is assessed individually).

Another problem is vague quality and material specifications. The developer says, “build me a house from high-quality concrete,” but does not specify the concrete class, manufacturer, or processing requirements.

The construction company chooses a cheaper concrete that may be structurally acceptable and meets general standards, but it is not what the developer had in mind. The developer then claims the construction is of poor quality, while the construction company claims it is performing under the contract.

Without specific specifications in the contract and the design documentation, the court typically rules in favor of the construction company, because the client should have clarified the requirements.

Budget ambiguities are also common. The contract sets the price “from amount X,” rather than a specific sum. During construction, additional works are identified that were not included in the design, and the construction company invoices tens of percent more.

The developer feels cheated, but the contract does not allow for an effective defense. A high-quality contract must include a priced bill of quantities with a specific description of each item and a unit price.

Missing technical specifications are also a problem. The developer orders a “modern roof,” but the design documentation does not specify the pitch, material quality, insulation, or ventilation. The construction company then chooses the cheapest option, which may be technically acceptable, but does not meet the physical requirements for the location (e.g., the roof pitch is not sufficient for snow in a mountain area).

The developer later deals with leaks and other issues. In such cases, the contractor is liable for defects in the work if they used unsuitable materials or technology, even though, based on the specifications, they could and should have expected specific functional properties (e.g., snow resistance).

If the contractor did not identify that the solution proposed in the design documentation is unsuitable for the location and did not warn about it, they are liable. However, the client should prevent such situations by ensuring clear specifications in the design documentation.

What happens when the brief is wrong during construction: obligations of all parties

Once construction begins, all involved parties – the developer, the designer, the developer’s technical supervisor, and the construction company – have specific obligations towards each other. If someone fails to meet them, it may lead to liability for defects in the construction.

The construction company’s obligations during construction

The construction company is obliged, without undue delay, to notify the client (or the developer’s technical supervisor, as applicable) if it notices that the project documentation contains errors or ambiguities that prevent proper performance of the construction.

It must also give notice if the instructions provided by the client are impossible to perform or would lead to defects in the work. Likewise, it is obliged to give notice if conditions on site (for example, soil conditions, the presence of unknown infrastructure, etc.) differ from what the project documentation assumed.

These notices must be recorded in the electronic construction log (pursuant to Section 157 et seq. of Act No. 283/2021 Coll., the Building Act), with the exact date and details of who made the entry and who was notified. This is not merely a formality – in court proceedings, the electronic construction log is key evidence.

If the construction company missed these issues or failed to record them, the court will hold it liable for the resulting defects in the construction. This is important: if the construction company notices a problem and does not record it, it effectively becomes the author of its own problem.

The developer’s technical supervisor’s obligations

The developer’s technical supervisor must monitor the construction and notify all issues they notice. They have the right to enter the site at any time, inspect materials, and carry out measurements and tests.

If the technical supervisor finds that work is being carried out based on incorrect project documentation or an unclear brief, they must record this and notify both the site manager and the client.

A proactive technical supervisor is a way to prevent later disputes. If issues are identified during construction, they can be addressed at minimal cost. If they appear only after completion, this usually means high repair costs and lengthy court disputes.

The court also looks at what the developer’s technical supervisor failed to do. If the technical supervisor had the opportunity to detect a defect and did not do so, their absence or passivity may be interpreted as a failure on their part, for which they bear liability for damage caused by their professional negligence.

What the designer is required to do during construction

The designer is usually not physically present on site; however, as part of the performance of a contract for design works, author’s supervision may also be agreed. Author’s supervision (pursuant to Section 156 of Act No. 283/2021 Coll., the Building Act) ensures that the construction is carried out in accordance with the verified project documentation.

If author’s supervision is agreed, the designer should carry out inspection walks on site and verify that the construction is being performed in accordance with their project documentation. If, during construction, the designer finds that the construction company is doing things differently, they must record this and give notice.

If they fail to do so, they cannot later claim that the error is not theirs.

Important: If it is discovered during construction that the project documentation contains errors, the designer has a duty to correct it urgently. They cannot leave the construction company in uncertainty and then be surprised that the construction turns out incorrectly.

How disputes over construction defects are resolved: legal procedures and time limits

When construction is completed and the developer finds that things are not in order, the question is: how long do they have to seek a remedy, and how does it work legally?

The difference between apparent and hidden defects

Czech law distinguishes between two types of defects. Apparent defects are those that should be visible upon handover of the construction. If part of the construction is missing, or visible damage can be seen, this is an apparent defect.

The client must point out apparent defects without undue delay upon taking over the construction. If they fail to do so, it is presumed that the client accepted the construction without reservations.

Hidden defects are those that do not manifest immediately but only later – for example, leakage appears during the first rain, or insufficient insulation is discovered during winter.

For hidden defects, the client has a much longer period – the contractor’s liability for defects in the construction lasts 5 years from the handover of the construction (Section 2629 of the Czech Civil Code). However, the defect must be notified without undue delay after it is discovered.

This is critical: the client cannot wait 5 years and then suddenly claim that the construction has a defect. If they discovered the defect, for example during the first inspection of the foundations (which may be after half a year), they must notify it without undue delay – we would say within a week or two.

Time limits and formal notice

When the client discovers a defect, they must notify the contractor in a way that can be demonstrably delivered to the contractor.

Even though an email or SMS may in some cases be considered written form, for legal certainty the client should send a registered letter with return receipt, or obtain other demonstrable confirmation of delivery.

The absence of formal and provable notice may mean that the court later dismisses the client’s claim even if the defect exists, simply because the contractor will argue that it was not aware of anything.

The most common mistake owners make is telling themselves, “I’ll call the site manager.” The site manager may forget, and employees may fail to pass the information on.

When the client later seeks a remedy, the contractor claims it knows nothing. The site manager may not even remember it. Without written proof of notice, the client is in a very difficult position.

The process for addressing defects after handover

Once the client notifies a defect, there are three basic options. The first is removal of the defect. The client may request that the contractor remedy the defect. The contractor usually has the right to do so, unless it would be disproportionately costly.

The second option is a discount from the price. Instead of a repair, the client may have the price of the construction reduced by an amount corresponding to the cost of remedying the defect, or by the difference between the value of the work without the defect and with the defect.

The third option is withdrawal from the contract. If the defect constitutes a material breach of contract (for example, the construction threatens to collapse or is completely unusable), the client may withdraw from the contract and request a refund of the money paid. However, this applies only to very serious defects.

In practice, the most common solutions are a price reduction or an agreed repair. Courts generally side with the party that acted reasonably and in good faith – i.e., the client who gave timely notice, or the construction company that addressed problems in a timely manner.

How a court assesses liability for defects

When a matter ends up in court, the judge assesses several key issues. The court examines whether the construction had a defect at the moment of handover. In doing so, it takes into account the contractual specifications, the client’s requirements, construction standards, and industry practice.

Next, the court assesses whether the defect was caused by a breach of the contractor’s obligations. Here, the court examines whether the contractor acted contrary to the contract or the project documentation, or whether it failed to comply with its duty to warn of problems.

The court also determines whether the client could have discovered the defect during the handover of the construction. If so and the client did not state it, they typically lose the right to compensation for apparent defects.

Finally, the court addresses whether the client notified the defect without undue delay after they could have discovered it. If the delay was long and it is found that the client already knew about the defect, the court may not uphold the claim.

The court also looks at who drafted the contract. If the contract was drafted by the contractor and contains ambiguities, courts generally interpret those ambiguities against the contractor (the contra proferentem principle). If it was drafted by the client’s lawyer, the situation is the opposite.

Possible issues	How ARROWS helps (office@arws.cz)
The developer provided an unclear specification, and now the construction company is charging more.	ARROWS will help with a contract analysis and point out whether its wording entitles the construction company to additional claims. If the specification was clearly ambiguous, our attorneys in Prague will help negotiate with the construction company to obtain a refund or reduce the additional demands.
The designer prepared project documentation with errors, the construction is defective—who will pay for it?	ARROWS will ensure the claim is asserted against the designer for defects in the documentation they prepared. Our attorneys in Prague will assist with communication and negotiations with the designer’s insurer, where compensation is often resolved out of court.
The construction company did not warn about problems in the design during construction; later the construction proved defective.	ARROWS will argue that the construction company had a duty (under Section 2594 of the Czech Civil Code) to warn of problems and record them in the electronic construction logbook. The absence of such a warning constitutes a failure by the construction company, for which it is liable for defects in the work.
The developer does not know how to formally notify a construction defect so that they have evidence.	ARROWS will prepare a draft formal defect notice for the developer and ensure it is delivered in a provable manner (registered mail with return receipt, courier with confirmation, entry in the electronic construction logbook).
The construction has a hidden defect that manifested after 2 years; the developer does not know whether they can still demand a remedy.	ARROWS will help prove that the developer notified the defect without undue delay after they could have discovered it (the period is not a fixed 5 years from handover, but from observing the defect within the five-year warranty period). Our attorneys in Prague will provide a legal opinion or representation in court proceedings concerning compensation for the defect.

The role of a contract for work in preventing disputes

It is not an exaggeration to say that a well-drafted contract for work resolves 80% of future problems. Conversely, a poor or vague contract is an open invitation to trouble.

A specific practical example: How a contract can help a developer

Imagine that a developer orders a house for CZK 5 million. The contract says only “construction according to the project documentation”, with a price of CZK 5 million for a 15×20 m two-storey hall. During construction, it is discovered that the developer also wanted landscaping and an access road, which the construction company believed were not included.

The developer adds CZK 500,000, the construction company claims it is not in the project documentation. The court takes the project documentation, sees that the road and landscaping are indeed not included, and decides that the developer must pay for it.

However, if the contract clearly stated: “construction according to project documentation version 3.0 dated 1 March 2025, to be provided by the developer, and including: (a) the main hall, (b) landscaping according to the attached plan, (c) a concrete road 2 m wide”, then the situation would be clear and the developer would achieve their objective.

How liability differs for defects that exist at the time of handover

A very important legal distinction that developers often do not understand: we distinguish between defects existing at the moment of handover of the construction and defects that manifest only later.

Defects at handover

If the construction has a defect at the moment the developer takes it over (or should have discovered it by exercising ordinary attention), the developer must report it without undue delay, ideally immediately during the handover.

If they fail to do so, the contractor may later argue that the developer accepted the construction without reservations and that they can no longer rely on the defect. This is very unpleasant for the developer, because they make a list of defects and outstanding works on the spot, based on a visual inspection.

These are not proper technical tests—the developer often cannot tell that the foundations are defective because they are backfilled.

This is why the client should prepare a handover and acceptance report immediately after taking over the works, containing a list of all visible defects and unfinished items. The court will then work with this list.

Defects that appear later (hidden defects)

If a defect only becomes apparent later (for example, leaking starts during the first heavy rain), the client has a longer period of time. The contractor’s liability for defects in the construction works lasts 5 years (Section 2629 of the Czech Civil Code).

However, the defect must be notified without undue delay after it is discovered. This usually means within a week or two, not months.

Legally, the situation is as follows: if the defect arose due to the contractor’s breach of contractual obligations during the construction (for example, using the wrong material, poor workmanship, etc.), the contractor is also liable for defects that only became apparent after the handover, provided the client notifies them in time.

However, if the client waited, for example, 2 years, reported nothing, and only now comes and says “I have a defect”, the construction company may argue that it is not possible to prove when the defect arose and whether the client already knew about it at the time of handover.

In such a case, the situation becomes very complicated and usually ends in favour of the construction company.

Final summary

A situation where the client provided the construction company with incorrect or unclear specifications is one of the most common causes of conflicts in the Czech construction sector. However, the legal framework is relatively clear: the client bears primary responsibility for the quality of the specifications.

All parties (the designer, the construction company, and the client’s technical supervisor) have duties to ensure that issues arising from unclear specifications are addressed in time and that clear evidence is created.

The key takeaway for clients is: a well-prepared contract for work with a clearly defined scope, price, and schedule is the best investment in preventing future disputes.

If the client pays attention to this from the very beginning of the project, they will avoid enormous costs, delays, and legal battles.

In practical terms: the client should engage a high-quality designer who will prepare detailed project documentation; the contract should clearly define the scope of the works, the price for individual items, and milestones with penalties; the client should hire an independent client’s technical supervisor to monitor the construction; and the client should always retain part of the payment (retention) until the end of the warranty period.

If problems have already arisen – the construction is defective, the client and the construction company disagree, it is unclear who pays what – it is absolutely essential to secure legal representation without delay.

Construction disputes in Czech courts take years and cost hundreds of thousands to millions of Czech crowns. The rules described here are simplified; in real-life situations there are exceptions, procedural details, and nuances that can significantly affect the outcome.

The attorneys at ARROWS advokátní kancelář focus specifically on construction matters, have experience with cases involving poor specifications, and understand court practice. When things get complicated, it is better to ask in advance – contact office@arws.cz.

FAQ: Clients and liability for construction specifications

1. Must the project documentation be prepared by a professional, or can the client prepare it themselves?
The project documentation must be prepared by an authorised person, typically an authorised engineer or architect. Act No. 283/2021 Coll., the Building Act, imposes an obligation to submit project documentation prepared by an authorised person for the purposes of building permitting proceedings. If the client prepares the documentation themselves without the required authorisation and it is later found that it does not comply with Czech building law, the client is responsible for that. In court, the argument would be that the client should have ensured a qualified designer who is an authorised person. ARROWS advokátní kancelář can also assist with a legal analysis of whether specific project documentation complies with the Building Act and related regulations – write to office@arws.cz.

2. What if the designer prepares the documentation according to the client’s specifications, but it later turns out that it is not technically correct from a construction perspective?
The designer is liable. The designer is a professional who has a duty to act with due professional care. If the client says “I want a two-storey house”, the designer has a duty to prepare it correctly from a construction perspective and in compliance with legal regulations. They cannot say “the client wanted it, it’s not my fault”. The designer is responsible for ensuring that the documentation complies with construction standards, the Building Act, and is feasible. If the documentation contains errors, the designer must correct them. Of course, the client must complain without undue delay – if they try to carry out the construction and only complain afterwards, the situation will be more complicated.

3. If we, as the client, have several designers and would like to choose the one whose documentation we like – is that a problem?
It is not a problem, provided it is clearly agreed in the contract. The client may commission several draft designs, choose one, and then have it developed in detail. However, this must be done with the knowledge of all parties so that a problem does not arise later, for example, where one designer believes their documentation will be used, another designer believes theirs will be used, and a conflict results. If selection among designers is intended, the client should clearly agree contractually how the selection will be carried out and who retains the rights to the documentation they prepared.

4. What is the difference between the client arranging technical supervision and the construction company arranging it?

Technical supervision arranged by the construction company is usually part of its internal processes and primarily looks after the construction company’s interests – it is not neutral. The client’s technical supervision arranged by the client is paid by the client and has a duty to look after the client’s interests. These are two different roles. Ideally, the client has their own independent client’s technical supervisor who monitors the construction and protects the client’s interests. The construction company has its site manager who manages the execution of the works. If the contract does not clearly state that the client has their own client’s technical supervisor, the construction company may claim that it arranged the supervision. The result is that the client has no protector. The attorneys at ARROWS help clients draft contracts that clearly define the role of the client’s technical supervisor – just contact office@arws.cz.

Disclaimer: The information contained in this article is for general informational purposes only and serves as a basic guide to the issue as of 2026. Although we strive for maximum accuracy, laws and their interpretation evolve over time. We are ARROWS Law Firm, a member of the Czech Bar Association (our supervisory authority), and for the maximum security of our clients, we are insured for professional liability with a limit of CZK 400,000,000. To verify the current wording of the regulations and their application to your specific situation, it is necessary to contact ARROWS Law Firm directly (office@arws.cz). We are not liable for any damages arising from the independent use of the information in this article without prior individual legal consultation.

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