25 August 2026
An owner who is refurbishing anyway need not have the installation inspected twice. The ESTI decides case by case — and what carries the decision is the defect list.
A case that comes up more often than it is discussed: the periodic inspection is due, and the owner is planning a full refurbishment anyway. Inspecting twice, once before and once after, makes little sense on the merits — the installation that would be checked will no longer exist in a year.
The NIV (Low-Voltage Installation Ordinance) provides for this case.
If the owner intends a full refurbishment or renovation of his electrical installations, the ESTI (Federal Inspectorate for Heavy Current Installations) decides case by case to what extent deadline extensions can be granted.
«Case by case» is meant literally. There is no entitlement and no form that triggers the extension automatically. There is a decision, and that decision has criteria.
As the ESTI describes it, such an extension depends essentially on
Both come down to the same thing: the ESTI extends the deadline for someone who is demonstrably under way — not for someone who has not yet started. The extension is not a postponement of the work but the recognition that the work is already in progress.
The contractor is the one who produces the evidence. The owner files the application, but what he can enclose with it comes out of the workshop and the building site.
That makes three things more valuable than they look at the moment they are created:
A contractor who keeps all this anyway writes the application in half an hour. One who has to hunt it all down does not write it at all — and has the installation inspected twice.
Two deadlines that regularly get mixed up in conversation:
The difference is not academic: the first is a deadline, the second is a decision. More on the first case in the article «The deadline for the safety certificate has passed»; which inspection interval applies in the first place is shown by the inspection interval calculator.
Source: Federal Inspectorate for Heavy Current Installations ESTI, information sheet «Periodische Kontrolle der elektrischen Installationen» (periodic inspection of electrical installations), October 2017. This article is not legal advice; the ESTI decides on any deadline extension.
We look at a real week from your business — 45 minutes, at your place or on screen.