15 September 2026
A ZEV remains permitted as long as PV production reaches at least 10 percent of the connection capacity — and that same connection capacity grows as soon as a wallbox without load management comes to the building. What electrical contractors should therefore check before the quote.
If an apartment building already has a self-consumption community (ZEV, Zusammenschluss zum Eigenverbrauch) and the same property is now to get wallboxes, two seemingly separate questions depend on the same figure: the connection capacity of the building connection. If the new charging infrastructure raises this connection capacity, the minimum PV production a ZEV needs to remain permitted rises too. Anyone who does not check this before the quote risks a ZEV that slips below the legal threshold because of its own wallbox installation.
A ZEV is a self-consumption community: several end consumers on one building connection who consume self-produced electricity among themselves without using the distribution grid for it. A community is only permitted if the production output of the system reaches at least 10 percent of the connection capacity of the community (Art. 15 para. 1 EnV, the Energy Ordinance) — the 10 percent threshold, covered in detail in the article "ZEV: the 10 percent, the timing and the costs".
The connection capacity is the maximum power released by the distribution system operator for the building connection point. The same quantity also decides matters on the charging-infrastructure side: if more than one charging station is operated on a building connection, the grid can, according to the VSE information sheet "Electromobility — Charging stations", be heavily loaded, which is why charging stations above 3.7 kVA must be controllable by the grid operator and the distribution system operator must be contacted before installation — details are in the article "Wallbox in condominium ownership". If the connection capacity stays the same, nothing changes for the ZEV. If it has to be raised, the denominator of the 10 percent calculation grows too.
A worked example shows the mechanism without claiming to describe a real case: a property with 50 kW of connection capacity and a PV system with 6 kW of production output sits at 12 percent — above the threshold. If the connection capacity rises to 65 kW because of new wallboxes without load management, the same share falls to around 9.2 percent — below the threshold, without anything having changed on the PV system itself.
This concerns two different situations, which need to be kept apart before the quote: a PV system newly planned for a ZEV, on a building that already has or is to get wallboxes — there, the actual connection capacity, sized for the charging infrastructure, belongs in the calculation of the module output required. And a ZEV that is already running and is now getting wallboxes — on which, see the next section.
The Energy Ordinance deals with this case expressly: if an existing ZEV subsequently falls below the 10 percent threshold, it can only be continued if the reasons for the change arose with the existing participants (Art. 15 para. 3 EnV).
For a wallbox, in practice this means: if a unit owner who already participates in the ZEV retrofits a charging station of their own and the connection capacity of the building connection rises as a result, the reason lies with an existing participant — according to the wording of the provision, the ZEV continues, even if the ratio falls arithmetically. If, on the other hand, the same wallbox came into the building with a new participant — for example because a previously empty unit is let and fitted with its own charging station — the starting position is different, and the grid operator or, in a dispute, the competent court decides the individual case.
A load management system distributes the power drawn by several charging stations at one building connection point so that the permitted connection capacity is not exceeded — described in the article on the wallbox in condominium ownership, with the two technical approaches the VSE information sheet names. For a property with a ZEV there is a second benefit: if the connection capacity stays unchanged thanks to load management, the 10 percent threshold stays unchanged too. A controllable charging system therefore not only saves the fee for raising the connection capacity, but may also keep alive an existing ZEV that an uncontrolled charging infrastructure would have pushed below the threshold.
For a property that has or is to get both a PV system with a ZEV and wallboxes, the connection capacity belongs in the quote as one shared quantity, not as two separate items:
Does a wallbox count towards the connection capacity that is decisive for the ZEV's 10 percent threshold? Yes, indirectly: if the new charging station raises the connection capacity of the building connection released by the distribution system operator, the denominator of the 10 percent calculation under Art. 15 para. 1 EnV grows too.
Can an existing ZEV fall below the threshold because of a new wallbox and still continue? Yes, provided the reason for the higher connection capacity lies with an existing participant (Art. 15 para. 3 EnV) — for example because a unit owner who already participates in the ZEV retrofits a wallbox of their own.
Does load management prevent the connection capacity having to be raised for a wallbox? Often, yes: a controllable charging system that spreads the load across several charging stations often makes raising the connection capacity unnecessary — and at the same time protects the 10 percent threshold of an existing ZEV.
Who decides whether the connection capacity has to be raised for a new wallbox? The distribution system operator, on the basis of the technical connection request (TAG), which has to be submitted before construction of the charging infrastructure begins.
Sources: Energy Ordinance (EnV, SR 730.01), Arts. 14, 15 and 16, fedlex.admin.ch. Energy Act (EnG, SR 730.0), Arts. 17 and 18, fedlex.admin.ch. Association of Swiss Electricity Companies (VSE/AES), information sheet "Electromobility — Charging stations", strom.ch. The worked example illustrates the statutory formula and does not describe a real individual case. This article is not legal advice; in an individual case, the grid operator or the competent court decides.
We look at a real week from your business — 45 minutes, at your place or on screen.