Grid connection (Hausanschluss) · Glossary

The Hausanschluss is the technical link between a building and the public electricity grid. It connects the low-voltage grid of the local grid operator with the electrical installation in the building. It also determines how much power is permanently reserved at this point. In Germany, the Hausanschluss is usually built as a three-phase connection. For the end of the connection, the Low Voltage Connection Ordinance (NAV) specifies a voltage of approximately 400 or 230 volts at approximately 50 hertz. In legal terms, the NAV speaks of the Netzanschluss (grid connection). In everyday use, this connection of a building to the low-voltage grid is usually called the Hausanschluss.

What is part of the Hausanschluss and what is not

For Germany, § 5 NAV sets the boundary: the connection begins at the branch point of the low-voltage grid and ends with the service connection fuse. Exceptions apply only if something different has been agreed. The Hausanschluss therefore typically includes the service line from the street to the building and the service connection box with the service connection fuses. Under § 8 NAV, these parts belong to the grid operator's operating facilities. Only the grid operator may maintain, renew, modify or disconnect them. Connection users must not interfere with them. They must report damage or missing seals without delay.

The meter location, by contrast, is not part of the Hausanschluss, even though this is often claimed. Under § 13 NAV, the connection user's electrical installation, i.e. the customer installation, begins downstream of the service connection fuse. This also includes the meter cabinet and the main lines. The connection user is responsible towards the grid operator for their proper installation, modification and maintenance. Excluded are metering devices that do not belong to the connection user, such as a meter owned by the metering point operator. Apart from the grid operator, only installation companies entered in a grid operator's installer register may carry out work on the customer installation. This requirement does not apply to pure maintenance. An exception to this is the section between the service connection fuse and the metering device, including the metering device itself: there, a registered company is also required for maintenance.

The Hausanschluss is also not the same as the electricity meter or the electricity contract. An electricity meter measures consumption and feed-in but creates no additional capacity. The supply contract determines who supplies the energy. The NAV expressly clarifies that use of the connection does not include the supply of electricity. The grid operator, not the supplier, decides on the connection capacity. The general term is grid connection. Large commercial or industrial customers are often connected at medium voltage. The NAV does not apply to them, as it only governs connections to the low-voltage grid.

Power rather than annual consumption

What matters for the Hausanschluss is not annual consumption in kilowatt-hours but the power drawn at the same time. Under § 4 NAV, the grid connection contract should state the power to be reserved at the end of the connection. An analogy helps: kilowatt-hours correspond to the amount of water flowing through a pipe over a year. Kilowatts correspond to the pipe's cross-section, which limits how much fits through at any one moment. A frugal household can therefore briefly need a great deal of power if an instantaneous water heater, cooker, heat pump and wallbox all run at once. A building with high consumption, on the other hand, may place little strain on the grid if the load is spread evenly or controlled. An electric car can charge overnight at a few kilowatts or in a short time at high power. In the end, the same amount of energy is in the battery, but the load on the connection is entirely different.

The service connection fuse protects the service line and limits the load at this point. However, it does not indicate how many houses along a street can draw high power at the same time. Grid operators plan with a simultaneity factor, because not all households ever need their peak power at the same time. When new loads run more simultaneously, this assumption loses validity. Examples are electric cars charging in the evening or heat pumps on cold days. In that case, the individual connection may be adequately protected while the local grid or the local substation reaches its limits.

Wallbox and charging equipment: notification and consent

Under § 19(2) NAV, additional consuming devices must be reported to the grid operator if they increase the power to be reserved or can be expected to cause grid disturbances. Charging equipment for electric vehicles, including any wallbox, must in principle always be reported before commissioning. In addition, prior consent from the grid operator is required if all charging equipment of an electrical installation together has a rated power of more than 12 kilovolt-amperes. The grid operator must then respond within two months. If it refuses, it must state the obstacle, possible remedies and the time needed for them.

In practice this means: a single 11 kW wallbox must be reported, whereas a 22 kW wallbox requires the grid operator's consent. However, the decisive factor is the total per installation. Two 11 kW wallboxes at one Hausanschluss together exceed the 12 kVA limit and likewise require consent. The reason for the rule is not that 22 kW would be technically unusual. Rather, many vehicles charging at the same time can place heavy strain on the local low-voltage grid.

Heat pumps and controllable consumption devices

A heat pump often draws only moderate power but runs for long periods on cold days. Heating elements or hot-water cycles can temporarily increase the load. For grid operation, the load profile over time therefore matters more than annual consumption. Since 1 January 2024, § 14a EnWG (Energy Industry Act) applies in the version set out in the Federal Network Agency's determination. Accordingly, newly connected controllable consumption devices in the low-voltage grid with a grid connection power of more than 4.2 kW must allow the grid operator to throttle them. These include heat pumps, wallboxes, air conditioners and storage systems that draw electricity from the grid. In case of impending overload, the grid operator may temporarily limit consumption. It may not switch off completely: at least 4.2 kW must remain available. With direct control, this value applies in principle per device. With control via an energy management system, the grid operator calculates a joint minimum power for all devices and takes a simultaneity factor into account.

Controllability does not enlarge the Hausanschluss. However, it helps to make better use of the existing capacity. In addition, load management within the building can prevent theoretical load peaks from arising in the first place, for example by reducing the wallbox's charging power while the cooker is running.

Photovoltaics and storage

A photovoltaic system generally feeds in via the same Hausanschluss when it generates more than is consumed in the building. The electricity then temporarily flows in the opposite direction. Low-voltage grids were formerly planned mainly for drawing power from the grid. Many small feed-in installations therefore change voltage maintenance, load flows and protection concepts. Whether a larger system can be connected without grid reinforcement thus also depends on the absorption capacity of the local grid. Legally, note the following: the NAV expressly does not apply to the connection of installations that generate electricity from renewable energies. Separate rules apply to them, above all under the EEG (Renewable Energy Sources Act), as well as the grid operator's technical connection conditions. A battery storage system can smooth feed-in peaks. Without sensible control, however, it can also increase the load on the grid, for example when many storage systems charge at the same time.

Costs and responsibilities

Under § 6 NAV, the grid operator establishes the Hausanschluss. It determines the type, number and location of the connections and must involve the connection user and take their interest in low costs into account. The connection user must provide a suitable location for the service connection box. As the technical standard, the NAV refers to DIN 18012 in this respect. Under § 9 NAV, the grid operator may demand the necessary costs for establishing or modifying the connection, including as a flat rate. Under § 11 NAV, a construction cost contribution (Baukostenzuschuss) may be added for the expansion or reinforcement of the local low-voltage grid, including the transformer stations. This contribution may cover no more than 50 percent of these costs. It may only be levied for the part of the connection capacity above 30 kW. In the event of a substantial later increase in capacity, a further contribution is possible. Connection costs and construction cost contribution must be shown separately. Which technical requirements apply in detail is determined by each grid operator in its Technical Connection Conditions (§ 20 NAV).

Disputes often arise when users see a new wallbox or heat pump as a mere equipment purchase. The grid operator, by contrast, must assess it as a change in connection capacity and load behaviour. Anyone planning a wallbox, heat pump, photovoltaics or storage should therefore clarify early on: How is the connection protected? What power has been agreed? Is the meter location sufficient? How capable is the grid at the site?

Sources

Niederspannungsanschlussverordnung (NAV) — Bundesministerium der Justiz / Bundesamt für Justiz (gesetze-im-internet.de); Stand: zuletzt geändert durch Art. 9 G v. 18.12.2025. §§ 1, 4, 5, 6, 7, 8, 9, 11, 13, 20
§ 19 NAV Betrieb von elektrischen Anlagen, Verbrauchsgeräten und Ladeeinrichtungen, Eigenanlagen — buzer.de (Wiedergabe des Verordnungstexts); unbekannt. § 19 Abs. 2 Sätze 2–5
Netzanschluss — Bundesnetzagentur; unbekannt. Abschnitt zu Ladeeinrichtungen
§14a EnWG Steuerbare Verbrauchseinrichtungen – Integration von steuerbaren Verbrauchseinrichtungen — Bundesnetzagentur; unbekannt. Verbraucherportal, Abschnitte zu Anwendungsbereich und Mindestleistung

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Edited by eCMS on 12.11.2026 05:05