4 September 2026
"NPK support" appears on many vendors' websites and rarely means the same thing. What the catalogue actually prescribes — a structure and reference values — and where your own costing step only begins.
A tender arrives structured according to the NPK, and the quote is meant to answer in the same order. That far, the catalogue is unambiguous. What it does not prescribe is the price behind it — and that is exactly where what a vendor's website means by "NPK costing" parts ways with what an electrical contractor actually calculates with it.
The NPK (Normpositionen-Katalog, the Swiss catalogue of standard construction items) is published by CRB — the Swiss Centre for Construction Rationalisation — for the whole of construction: building, civil engineering, building services. Around 200 chapters in total, arranged in ten chapter groups from 000 to 900. For the electrical trade the relevant group is 500 "Electrical installations", and there the trade association EIT.swiss publishes the trade-specific products: the NPK as a set of binders, as a compact A5 handbook for the site and as an eBook, together with the costing aids that belong to the catalogue. According to EIT.swiss, some 14'000 service items are available for electrical installation alone.
That explains why "NPK support" in a piece of software can mean three different things: importing the full catalogue under your own licence, taking over only the structure of a specific tender, or storing your own costing item with a material factor. The article on trade software draws that line from the software's side; this one is about what lies behind it.
The chapters are ordered by building component, not by trade within the electrical installation:
A quote that answers in this structure can be compared with the tender directly by the planner or the client. A quote in an order of its own — even one complete in substance — hands them the very work the catalogue is supposed to save them.
An NPK item describes a service in standardised wording together with a standard time — how long the item takes on average. What it does not contain is a ready-made amount in francs: labour rate, material price and surcharges differ from one contractor to the next, and for that EIT.swiss provides its own price-basis calculation — a detailed table covering four installation types and two material categories, plus a simplified version for smaller firms. This firm-specific price basis, multiplied by the standard times of the chosen items, produces what is called the target revenue (Sollerlös), which EIT.swiss adjusts for inflation every year as of January.
Anyone who wants to work out this step themselves can do it by hand. In practice it runs through one of the costing programs certified by EIT.swiss — AbaBau and VOLTA among them — which import the catalogue directly and apply the price basis automatically to every item chosen. The data licence for the catalogue itself is bought separately from the software; a program that advertises NPK support therefore does not necessarily come with the items.
The NPK is revised every year, because products and working methods in the electrical trade change constantly. The 2024 edition shows this at a point many contractors are feeling in practice right now: chapter 511 gained new administrative texts for connection applications and the ZEV (self-consumption community), and chapters 531 and 543 were extended to charging stations and load managers with up to 20 charging points, as well as OCPP-capable systems. Anyone quoting for a wallbox now finds the item in the catalogue instead of assembling it themselves — which does not replace the notification duty and the consent a wallbox still needs. See the articles "Wallbox in condominium ownership" and "Wallbox in a rented flat".
The structure decides whether a quote is readable in a comparison; the price basis decides whether it covers its costs. Both are in the catalogue, but only the structure is the same for every firm — the price basis is the firm's own and stays that way even with the best software. A checklist of what that means for choosing software is in the article "Trade software for electrical contractors".
Sources: CRB — Swiss Centre for Construction Rationalisation, crb.ch, pages "Normpositionen-Katalog NPK" and "NPK-Kapitelgruppen, -untergruppen und -Kapitel", retrieved on 4 September 2026. EIT.swiss, eit.swiss, pages "NPK — Der Normpositionen-Katalog", "Arbeitshilfen — NPK" and "Der NPK 2024", retrieved on 4 September 2026. This article describes the structure of the catalogue and its costing aids, not the prices or standard times of individual items — these change with every edition and are binding only in the licensed source.
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