How far should you live from a power line?

Question

What is a safe distance from a high-voltage power line?

Answer

Magnetic fields beneath a loaded transmission line typically fall from tens of milligauss at the conductors to residential background by roughly 30–60 m, depending on current, conductor height and phase arrangement. No jurisdiction sets a health-based setback; the Netherlands uses a 0.4 µT policy target for new lines and Switzerland applies a 1 µT installation value at sensitive locations, both precautionary rather than effect-based. Because line loading changes hourly, a 24-hour log at the property is worth more than any distance rule.

Related records

• High-voltage transmission line

  Fields directly beneath a loaded transmission line reach tens of milligauss and fall off roughly with distance for a balanced three-phase circuit, reaching background at 30–60 m for typical loadings.

  Sources & emitters

• Swiss installation limit value for power lines

  1 µT (10 mG) magnetic flux density at places of sensitive use — the strictest power-frequency installation value in force in Europe.

  Exposure limits

• ELF magnetic field survey

  A source-finding walkthrough plus a 24-hour log, because power-frequency magnetic fields track electrical load and a spot reading answers almost nothing.

  Measurement protocols

Sources

1. niehs-emf Electric and Magnetic Fields — National Institute of Environmental Health Sciences. government, link checked 2026-08-12.
2. ch-onir Ordinance relating to Protection from Non-Ionising Radiation (ONIR / NISV, SR 814.710) — Swiss Confederation, 2000. regulation, link checked 2026-08-12.
3. who-elf Electromagnetic fields and public health: exposure to extremely low frequency fields — World Health Organization, 2007. government, link checked 2026-08-12.