Variation claims rarely fail on the merits. They fail on a notice that was missing or late. What §§ 6 and 2 of the German VOB/B require, what 'without undue delay' means, and what a site report must look like for extra work and impediments to be recognised later.
The screed is not ready for covering, the preceding trade is behind schedule, the client wants a different tile from the one ordered. Something that was not in the contract happens on every site every day. Whether the business ends up getting money or time for it is not decided at the final invoice, but at the moment it happens.
The notice of impediment: without undue delay, in writing
§ 6 (1) VOB/B (2016 edition) provides that if the contractor considers itself impeded in the proper execution of the work, it must notify the client without undue delay and in writing; if it fails to give notice, it is only entitled to have the impeding circumstances taken into account if the client was evidently aware of the fact and its impeding effect (unofficial translation).
Two words carry the whole provision: without undue delay, and in writing. Without undue delay means without culpable hesitation. An impediment that arises on Monday and appears in Friday's weekly report is a risk. In writing means a verbal remark to the foreman is not enough. Whoever omits the notice only retains claims if the impediment was "evident" to the client, and in a dispute the contractor has to prove that.
What is at stake is shown by § 6 (2) VOB/B: execution periods are extended to the extent the impediment was caused by a circumstance within the client's sphere of risk (unofficial translation). And § 6 (6) VOB/B expressly ties the claim for damages and for reasonable compensation under § 642 of the German Civil Code to the notice under subsection 1 having been given.
It is not the impediment that costs the business money. It is the missing notice.
The variation: announce it before you start
Additional work follows a similar logic. § 2 (6) no. 1 VOB/B: if work not provided for in the contract is demanded, the contractor is entitled to special remuneration, but must announce the claim to the client before starting to execute the work (unofficial translation). For changed work, § 2 (5) VOB/B says a new price is to be agreed and that the agreement should be reached before execution.
The typical mistake is not that the business forgets the extra work. It is that the fitter does it because the client happens to be standing right there, and the variation is only written up in the office in the evening, when announcing it "before starting to execute the work" is no longer possible.
What belongs in the site report
Both cases need the same document: a dated entry recording what happened, who caused or ordered it, which work is affected, what the consequence is for time and cost, and to whom it was communicated and when. A time-stamped photo proves the condition. The note that the site manager was informed proves the notice. Together they are the basis on which variation tracking under VOB/B works at all.
That includes the notice of concerns: under § 4 (3) VOB/B, the contractor must inform the client without undue delay, if possible before starting work, and in writing, of any concerns about the work of other contractors (unofficial translation). Whoever lays flooring on a screed that is not ready without having flagged it in writing may later be liable for the damage themselves.
Why capture in the moment matters
The requirements "without undue delay" and "before starting to execute" cannot structurally be met by an evening report. They can be met when the report is created where the impediment occurs. Whoever speaks the impediment, the cause and the action taken while standing in front of the damp screed has a time-stamped entry that can be sent as the notice and filed as the proof. Scrypa Trades captures site reports and variations exactly like that and transfers them, structured, into your software.
This article gives a general account of the legal position under the German VOB/B (2016 edition) and is not legal advice for individual cases. Whether VOB/B applies and which form of notice was agreed depends on your contract.
The figures in this article are illustrative and based on industry studies of voice-based documentation. They do not replace an assessment for your own organisation.