17 September 2026
In a spot check, the owner pays if defects are found — otherwise the body that ordered it pays (Art. 39 NIV). If defects are not remedied within the deadline, the Inspectorate takes over enforcement, at the owner's expense.
Who pays for a spot check is settled unambiguously by Art. 39 of the NIV (Low-Voltage Installation Ordinance): if defects are found, the owner of the installation bears the costs; if the installation is free of defects, they fall to the body that ordered the check — the grid operator or the Inspectorate. If an ordered remedy of defects has no effect, the Inspectorate (ESTI, the Federal Inspectorate for Heavy Current Installations) takes over enforcement and can have the defects remedied by third parties at the owner's expense (Art. 40 NIV).
The defect list that lands in the letterbox after an inspection almost always raises the same question for the electrical contractor, before the actual quote is written: is this a job the owner pays for anyway — or is an authority already involved, bringing its own deadline and its own cost consequences? The answer depends on which inspection found the defects and who ordered it.
A defect list is the written list of the defects found during an inspection — the term the ESTI also uses in its practice when an inspection body documents the results of an inspection. The NIV itself prescribes no particular form for this document. It only obliges the competent body to set a reasonable deadline for remedying the defects found (Art. 40 para. 2 NIV) — which in practice presupposes a written, dated list, without itself requiring one. For the contractor who draws it up, it is nevertheless more than a form: how a defect list becomes a quote is set out in the article «Commissioning an inspection body or agency».
For a spot check, the rule is a pure condition. A spot check is an inspection that the Inspectorate or the grid operator orders independently of the current inspection interval, when there is reason to believe that an installation does not comply with the NIV (Art. 39 para. 1 NIV). The costs are then governed as follows (Art. 39 para. 2 NIV):
For remedying defects, the question of costs is tied to the deadline, not to the inspection itself. For defects found when the safety certificate (Sicherheitsnachweis) is examined or during a spot check, the grid operator or the Inspectorate sets a reasonable deadline for remedying them (Art. 40 para. 2 NIV). If that deadline passes without action, the grid operator hands enforcement over to the Inspectorate; it sets a further deadline, and if that one also passes, it can have the remedy of the defects ordered from third parties at the owner's expense or cut off the power supply to the part of the installation concerned (Art. 40 paras. 1 and 3bis NIV).
What the NIV does not govern is the price of the inspection job itself — the appointment, the regular inspection within the inspection interval, and the remedy itself if it is carried out on time. That is a private agreement between the owner and the contractor commissioned, like any other quote. The cost consequences of Art. 39 and 40 NIV only apply once an authority has ordered the inspection or a deadline has passed without action.
The two bodies are not interchangeable, and the NIV separates them by the stage the procedure has reached:
The grid operator manages the ordinary case. It asks the owner in writing, at least six months before the inspection interval expires, to submit the safety certificate (Art. 36 para. 1 NIV), checks submitted safety certificates for completeness and rejects those that are obviously incorrect (Art. 38 NIV), and, together with the Inspectorate, orders spot checks and deadlines for remedying defects (Art. 39 para. 1, Art. 40 para. 2 NIV).
The Inspectorate (ESTI) takes over when the ordinary case does not work. It supervises the inspection bodies and the holders of an installation licence, inspects installations nobody else inspects, and decides in disputes whether an installation complies with the provisions of the NIV (Art. 34 NIV). If the safety certificate is not submitted on time despite two reminders, the grid operator hands enforcement of the periodic inspection over to the Inspectorate (Art. 36 para. 3 NIV) — the same handover as for a defect list not remedied on time (Art. 40 paras. 3 and 3bis NIV).
Two situations look the same to the customer and are not. If the job comes through the regular inspection interval, the remedy is a normal quote — the contractor prices it like any other job, and the deadline is the owner's business, not the NIV's. If the job comes through an ordered spot check or a remedy deadline already set by the grid operator, it is worth telling the customer early: if the deadline is missed, the matter escalates to the Inspectorate, and the cost of the remedy then ordered from third parties almost always exceeds what a timely quote would have cost. How the deadline for the safety certificate itself works is set out in the article «The deadline for the safety certificate has passed», and who may inspect and issue the certificate at all, in the article «Commissioning an inspection body or agency».
Who pays for a spot check? The owner, if defects are found. If the installation is free of defects, the costs are borne by the body that ordered the inspection — the grid operator or the Inspectorate (Art. 39 para. 2 NIV).
What happens if defects are not remedied within the deadline? The grid operator hands enforcement over to the Inspectorate, which sets a further deadline. If that one also goes unused, the Inspectorate can have the remedy ordered from third parties at the owner's expense or cut off the power supply to the part of the installation concerned (Art. 40 NIV).
Is the grid operator or the ESTI responsible? The grid operator for the ordinary case — deadlines, reminders, examining safety certificates. The Inspectorate once a deadline has passed despite two reminders, in disputes over compliance with the NIV, and wherever no other body inspects (Art. 34 and Art. 36 para. 3 NIV).
Does the defect list have to follow a particular format? The NIV prescribes no format. It only requires that a reasonable deadline be set for remedying the defects found (Art. 40 para. 2 NIV) — in practice documented as a written, dated list.
Sources: Ordinance on Low-Voltage Electrical Installations (NIV, SR 734.27), Art. 34, 36, 38, 39 and 40, fedlex.admin.ch, for the cost consequences of the spot check and of remedying defects and for the responsibilities of the grid operator and the Inspectorate. Federal Inspectorate for Heavy Current Installations ESTI, communication no. 2024-0802 «Sicherheitsnachweise nach Konkursen bzw. bei Wegfall der Aufsicht des fachkundigen Leiters», esti.admin.ch, for the term defect list (Mängelliste) as used in practice. This article is not legal advice; in case of doubt, the responsible grid operator or the ESTI decides.
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