Bedenkenanmeldung under § 4 para. 3 VOB/B: when you are liable if you stay silent

What the Bedenkenanmeldung is for

The contractor (Auftragnehmer) owes a work free of defects. But what if the defect is not due to your work, but to a mistake in the design, in the material supplied by the building owner or in the work of the previous trade? Two rules work together here:

• § 13 para. 3 VOB/B: If a defect is due to the specification, to instructions of the client (Auftraggeber), to materials or components supplied or prescribed by the client, or to the condition of earlier work by another contractor, the contractor is liable nonetheless, unless it has given the notice incumbent on it under § 4 para. 3.
• § 4 para. 3 VOB/B: Anyone who has concerns must notify them without delay, if possible before work starts, in writing. The client remains responsible for its information, instructions and supplies.

With the notice, you therefore shift the risk back to the party who caused it.

What concerns can relate to

§ 4 para. 3 VOB/B names three areas:

Under § 4 para. 2 no. 1 VOB/B, you carry out the work on your own responsibility and must observe the recognised rules of technology and statutory and official requirements. A specialist firm that can see that a plan breaches them must report it.

When the notice must be given

“Without delay – if possible before work starts.” That means: check the plan, material and substrate before starting, not only when things go wrong. Typical points in time:

• when clarifying the order and reviewing the plans,
• on delivery and goods-received inspection,
• when taking over the earlier work (handover of the substrate).

Anyone who only has concerns after work has started should still report them immediately, but liability for problems that were already apparent is harder to avert.

What the notice should contain

VOB/B requires written form, but no fixed wording. What is effective is what is specific and comprehensible:

1. Addressee, date, construction project, contract.
2. The point the concerns relate to (plan, item, material, earlier work).
3. What exactly you consider faulty or unsuitable and why (standard, manufacturer’s specification, measured value, photo).
4. Possible consequences if it is built that way (defect, damage, risk of accident).
5. Your proposal for a remedy or the request for a decision by the client.
6. Deadline for a reply.
7. A statement that if the work is carried out as instructed you accept no liability for resulting defects.
8. Evidence as an annex.

General sentences such as “we have concerns about the design” are not enough in a dispute. The more precisely you name the point and the consequence, the better you are protected.

And if the client insists on the instruction?

§ 4 para. 1 no. 4 VOB/B covers the case of instructions from the client that the contractor considers unjustified or inappropriate: it must raise its concerns, but must carry out the instructions on request, unless statutory or official requirements prevent it. If this causes an unjustified additional burden, the client bears the additional costs.

That means:

• If the client insists and you are sure it cannot be done that way: where there is a danger to life and limb or a breach of statutory or official requirements, you may and should refuse to carry it out.
• Otherwise you carry it out, document the instruction and your concerns and bill the additional costs.

How to enforce additional costs is explained in Nachtrag in a construction contract.

How to deliver the notice

• In writing and with proof of receipt. The client (not just the architect or site manager) should receive the letter.
• A copy to the designer if the contract provides for it or if the concerns relate to the designer’s work.
• Filing in the project folder with proof of delivery, photos and measurement records.

Typical mistakes

• Only said orally (“I told the foreman”).
• Too late: only after completion.
• Too general: without the point, the reason and the consequence.
• Sent to the wrong person.
• Wording without a decision: you do not ask how to proceed.
• Forgetting the statement that, if the client insists on the instruction, you only carry it out and are not liable.

Frequently asked questions

Sources and status

• § 4 para. 1 no. 4, paras. 2 and 3 VOB/B – execution (2016 version, checked against the statutory text in the BauWalker corpus)
• § 13 para. 3 VOB/B – defect claims
• Stand: 19.10.2026. How far a specialist contractor’s duty to check and warn extends in an individual case depends on case law and circumstances and was not evaluated here.
• Quotations of statutory text are given in translation; the German wording is authoritative.