Protection zones of transformer stations and MV lines: how many metres and what it means for your project

28 October 2026 · 5 min read

A protection zone arises by law and you will not find it in the land register. How many metres apply to a 22 kV line, a buried cable, a kiosk or pole-mounted transformer station or battery storage – and what may not be in the zone.

What a protection zone is

A protection zone is the space around a power line or an electrical station intended to protect the equipment from damage and people from injury. It arises by law (Czech Energy Act No. 458/2000 Coll., Section 46) on the day the equipment is permitted – it does not need to be registered or decided anywhere. For a developer this means a zone may lie on the plot that the land register says nothing about, and yet nothing may be built in it without consent. That is why checking protection zones is one of the first steps of a site check.

How many metres: lines

The width of the zone is measured horizontally from the outermost conductor or cable on each side.

Equipment	Protection zone
Overhead line 1 to 35 kV with bare conductors (the typical 22 kV line)	7 m
Overhead line 1 to 35 kV with insulated conductors	2 m
Aerial bundled cable 1 to 35 kV	1 m
Overhead line above 35 up to 110 kV – bare / insulated conductors	12 m / 5 m
Overhead line above 110 up to 220 kV	15 m
Overhead line above 220 up to 400 kV	20 m
Underground cable up to 110 kV (including low voltage)	1 m
Underground cable above 110 kV	3 m

For overhead low-voltage lines the Act sets no protection zone; for buried cables 1 m applies regardless of voltage. Lines built before 1995 may have wider zones under earlier regulations – for older 22 kV lines up to 10 m.

How many metres: transformer stations, plants and storage

Equipment	Protection zone
Outdoor electrical station and station above 52 kV inside a building	20 m from the fence, or from the outer face of the wall
Pole-mounted and tower transformer station (MV/LV)	7 m from the outer edge of the station's footprint
Kiosk (compact) and masonry transformer station (MV/LV)	2 m from the station's outer shell
Transformer station built into a building	1 m outside the enclosure
Power plant or battery storage connected at MV (1 to 52 kV), except solar PV	7 m from the fence or outer wall
Plant or storage connected at HV or to the transmission grid, except solar PV	20 m
Solar PV plant; plant above 50 kW connected at LV	1 m
Plant or storage up to 50 kW at LV	no protection zone

For the design this means two things. A kiosk transformer station needs only 2 m around it, so it fits even a cramped site; a pole-mounted one needs 7 m. And battery storage connected at MV has its own zone of 7 m from the fence – to be considered when placing it near the plot boundary and neighbouring buildings, alongside the clearances required by the fire safety solution.

What is not allowed in a protection zone

Without the written consent of the equipment owner (usually the grid operator) it is not permitted to erect buildings or place structures in the zone, to store flammable or explosive substances or to carry out earthworks. Nothing may be done there that endangers the reliability and safety of operation or hinders access to the equipment. Under an overhead line, vegetation may not exceed 3 m; above a buried cable, permanent vegetation may not be planted and machinery heavier than 6 tonnes may not cross.

Consent can be obtained: the operator issues it in writing and may set conditions – the method of crossing, protecting the cable with a duct, or supervision during excavation. For PV on a plot under a 22 kV line, for a storage fence near a cable or for a service connection routed in another network's zone, the consent is a routine part of the documentation's supporting documents.

When the equipment is in the way: relocation

If a line or a station stands where the building is to go, a relocation can be requested (Section 47 of the Energy Act). The relocation is carried out by the grid operator, but the costs are borne by whoever caused the need for it – that is, the developer. A relocation means a new route, consents of the affected landowners, easements and often a permit; in the construction schedule it is a separate item. More on cable routes and consents on the cable and line networks page.

How we identify protection zones

statements on existing utilities from the grid operator and other network owners – positions of lines and cables, including those that cannot be seen,
a survey of the existing state and a check on site – the conductor type (bare, insulated) decides the zone width,
plotting the zones in the coordination site plan and checking the clearances of the technology, fencing and service connections,
consents or relocations incorporated into the supporting documents of the permit documentation.

Zones of other networks – gas pipelines, water mains, telecommunication cables – have their own regulations and are handled the same way. A high-pressure gas pipeline additionally has a safety zone of tens of metres that can rule out a storage project altogether.

Frequently asked questions

Can I build PV under a 22 kV line?

Only with the grid operator's consent and on its conditions. In practice the panels are placed outside the zone, or the operator agrees to part of the zone provided the distances from the conductors are kept; access to the line for maintenance is also assessed.

How far from the plot boundary must a kiosk transformer station stand?

The protection zone is 2 m from the shell; by itself it does not prevent placement at the boundary as long as the zone does not reach into a neighbour's building, or the neighbour agrees. The deciding factors are rather the operator's requirements for access from public space and the fire clearances.

Does a protection zone apply to a low-voltage service connection to a house?

For a buried cable, yes – 1 m on each side; nothing may be built or planted above it without consent. For an overhead LV service connection the Act sets no zone, but safe distances under the standards apply.

Who pays for relocating a line that crosses our plot?

Whoever needs the relocation – that is, the developer. The exception is where the relocation is necessary because of the technical condition of the operator's equipment.

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