What the recognised rules are
Allgemein anerkannte Regeln der Technik, generally recognised rules of technology, are technical rules that have passed two stages:
| Stage | Content |
|---|---|
| Established as correct in science | the predominant majority of specialists regards them as sound |
| Proved correct and serviceable in construction practice | they are tested and not merely justified in theory |
Both stages must be met. A rule that is scientifically recognised but untested in practice is not yet a recognised rule of technology.
They need not be written down. Most are, in DIN standards, VDI guidelines or technical bulletins. In traditional trades, however, orally transmitted rules also exist, and these can even take precedence over written standards where they embody the more recent position. Their application does not depend on publication.
DIN standards are not legal norms
The Federal Court of Justice put it in a much-cited decision: DIN standards are not legal norms but private technical rules of a recommendatory character. That classification has been settled case law since.
They are published by a registered association. They do not apply by force of law unless expressly introduced as legal norms.
A proposition follows that is decisive in defect disputes. It concerns the relation between standard and rule.
A DIN standard may reflect the recognised rules of technology, fall short of them, or go beyond them.
All three occur. Technical rules develop continuously, while a standard fixes their position at the date of its adoption. An outdated standard thereby loses significance, because it no longer corresponds to the findings of theory and practice.
What governs is therefore not which standard applies but whether the work performed complies with the recognised rules of technology.
Three levels of technical requirement
Three terms are regularly conflated and denote different levels. They lie at different heights.
| Term | Requirement |
|---|---|
| Recognised rules of technology | scientifically recognised and proved in practice |
| State of the art | achievable; need not yet have proved itself in practice |
| State of science and technology | additionally covers the latest scientific findings |
The difference between the first two is proof in practice. The state of the art is the basis on which standards are prepared.
A surprising consequence follows: a newly published standard is not yet a recognised rule of technology, so long as it is not yet applied by the majority in practice.
Wording therefore matters in contracts. Agreeing the state of the art demands more than the recognised rules of technology, and agreeing the state of science and technology demands more still.
The presumption
A presumption has become established in the case law: the current version of a DIN standard carries the presumption that it correctly reflects the position of the recognised rules of technology. Its reach is now contested.
That presumption is rebuttable. Anyone relying on a departure must prove the contrary. That can succeed where the standard falls short of the recognised rules or has not established itself in practice.
Whether a standard is a recognised rule of technology in a given case is assessed in a dispute by experts. The court does not decide from its own expertise.
The presumption is contested
This is the most current point on the subject and is not reflected in older treatments. It concerns the presumptive effect of DIN standards.
| Development | Content |
|---|---|
| Two lines are diverging within the Federal Court of Justice | the senate competent for construction contract law and other senates assess the presumption differently |
| A higher regional court has taken up the criticism | it requires each standard to be examined individually |
| One argument from within the standards system itself is notable | the standards institute does not assume in its own principles that every standard reflects the state of technology |
In practice: failure to observe a DIN standard is not automatically a defect, and observing one does not automatically exclude a defect. On construction law questions it is advisable to follow the line of the senate competent for construction contract law.
What is owed contractually
Absent a differing agreement, the contractor tacitly warrants observance of the recognised rules of their trade. That holds both for contracts under the Civil Code and for contracts incorporating the VOB/B.
Two consequences matter in practice.
| Conclusion | Content |
|---|---|
| A breach is a defect even without damage | whether the departure had any effect is irrelevant |
| The date of handover governs | where the rules develop between contract and handover, the later position applies |
| A departure can be agreed | but it must be agreed, and the contractor must prove it |
Incorporating the VOB/B makes the technical conditions of contract, and thereby the relevant standards, part of the contract. The branch on the VOB/C within the tendering subject covers their effect.
What follows for tendering
Three consequences for drafting specifications. All three concern references to standards.
| Consequence | Content |
|---|---|
| Referring to a standard is not a guarantee of performance | citing a standard does not shift responsibility for the result |
| The edition belongs named | standards are maintained and updated, and the governing version must be settled |
| Equivalents must be admitted | references to technical specifications must carry an equivalence reservation under procurement law |
Related articles
This article reflects the position of the rules and case law at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.