Poor House Wiring Causes Strong Magnetic Fields

EMF from House WiringWhen we think about EMF in the home, we don’t usually think in terms of house wiring, but in houses where EMF radiation is higher than usual, poor house wiring is often the cause.

If wiring is well-designed and properly executed, background levels of low frequency EMF should be very low (less than 0.3mG), although there can be local hotspots substantially above this level in any house.

But in some houses, there can be large areas – sometimes whole rooms – where EMF levels can be elevated when certain electrical circuits are being used.

Why should you care about EMF levels in your home? Because EMF affects your body and may damage your health, especially if high emf levels are experienced over a long period (usually several years).

Let’s start by looking at localized EMF hotspots and their causes before going on to consider the larger problem created by incorrect wiring.

What causes Home EMF Hotspots?

Home EMF hotspots arise close to items such as electricity meters, not just Smart Meters. Expect high EMF readings near main distribution panels or fuse boxes, transformers, battery chargers, back-up power supplies and inverters. These hotspots often extend up to 6 feet (1.9 metres) from their source before the EMF radiation fades to background levels.

Other hotspots from installed electrical equipment such as florescent lights, light switches (particularly dimmer switches), heating panels, intercom base stations and air conditioning units usually have a shorter range. Also see our Electrical Appliances page.


How to Avoid Exposure to House-Wiring EMF

Avoiding EMF HotspotsIt really helps to be aware of the EMF hotspots in your home, so you can avoid spending large amounts of time exposed to a high EMF. See our EMF Protection Tips.

One way to prevent EMFs is to switch things off when you are not actually using them.

Take underfloor heating for example, which often creates massive EMF hotspots. You could switch it off when you enter a room. (It stays warm for hours.) Or have it switch on (by time switch) in your living areas for a few hours before you get up in the morning, and then switch off before you start using those rooms.

Another way to avoid exposure is to increase your distance from an EMF source. When you know the source, it is usually easy to avoid the EMF – you might have to move your favourite chair a couple of feet, or slide a bed along the wall. Speaking of walls…

Don’t forget that low-frequency magnetic fields will pass through walls without any trouble, so if your hotspot source is close to a wall, pay attention to what is on the other side too.

And in case you are wondering, you cannot make your house EMF-safe by growing radiation-absorbing pot-plants or plugging in special EMF filters, or wearing special skin patches, or surrounding yourself with weird radiation-absorbing gadgets.

None of these things has any effect on low-frequency radiation from house wiring, or its ability to harm you.


Badly-Wired Houses Cause High Home-EMF Levels

Apart from the EMF hotspots we have been discussing that are found in practically every home, there are some houses which contain more widespread EMF due to poor wiring practices. Some of these poor practices do not comply with the local electrical regulations either, so they may also be electrically unsafe.

Faulty wiringLet’s look at how bad wiring can create an EMF. This is going to be a little technical, so if you want to skip this section, be my guest. (And since I am not an electrician, please don’t rely on this information if you are attempting to fix any wiring problems yourself!)

Still here? Great.

Whenever a current flows through a wire, a magnetic field is created around that wire.

If the current is alternating, then the polarity of the magnetic field will also continually switch – from North to South to North to South – and so on. This creates a low-frequency magnetic field (50 or 60 cycles per second, depending on the mains electricity frequency) and it also creates a low-frequency electric field.

(These are the two components of electromagnetic radiation: electric and magnetic fields.)

The magnetic field is of particular concern, as it easily penetrates obstacles including thick walls, metal shields, or human bodies. Because it can penetrate a person’s body, it can harm the cells inside. Over a long period, this may damage a person’s health.

You may be wondering if ALL electrical wiring creates an EMF? 

Yes, it does. Even with good wiring, any current flowing in a live wire creates an EMF, and the current returning via the neutral wire does the same. But these two EMFs have opposite polarity. (When one is South, the other is North, and vice versa.)


So as long as the live and neutral wires run very close to each other, their EMFs overlap perfectly and cancel each other out, resulting in a net EMF of zero. But if they are not close together, they cannot cancel each other out, and a net EMF is the result.

Good electrical work looks neat tooWhen installed properly, live and neutral wires run together in the same cable jacket or conduit (usually with an earth wire as well).

But if the person doing the wiring is not aware of how it should be done, or breaks the rules, he could run the live wire through one path and the neutral through another, creating a high, unopposed EMF.

The electrical circuit will still work, because there is live and neutral current to power it.

BUT an EMF will be created around the live wire, and another around the neutral wire. The further apart these wires are from each other, the less cancelling effect there will be, so the resulting EMF will be larger – and stronger.

(Also, a stronger current flowing in the circuit will cause a stronger EMF.)

Examples of Wiring Faults Which Create an EMF

This is not the only way that poor wiring can create an EMF, or even the most common way.

A more complex example is when the neutral wire of one circuit is connected to the neutral wire of another circuit, when these should be kept separate. This creates an imbalance between the neutral and live wires in both circuits because some of the current which should return to the source via the first circuit’s neutral wire will instead return via the second circuit’s neutral wire, and vice versa. The circuits will still work well enough, but an EMF will be created around each.

Here are some common wiring faults which give rise to EMF inside houses (or offices or factories etc.)


  1. Neutral wires from different circuits joined together
  2. Inappropriate connection of a neutral wire to ground (including water or gas pipe)
  3. Incorrectly wired multi-way lighting circuits (where lights are controlled by two or more switches).
  4. Live and neutral wires in one circuit follow different routes.
  5. Ring circuits have been installed – see next.

Ring Circuits

In some countries (e.g. the U.K.) it is legal to connect a series of electrical sockets in a wired “ring.” Using this method, a connection to the power source is made at two points of the ring (the “ends”).

Ring Circuit can create EMF

Ring Circuit can create EMF

The live and neutral wires each form a ring, and both wiring rings follow the same physical route. But live current could take the path to a socket from one end of the ring, while neutral current could return from the socket to the other end.

This can happen if there is a bad connection or other resistance at some point in one circuit, as electricity will always flow through the circuit offering the least resistance.

The net imbalance between live and neutral current flow in parts of the circuit causes an EMF. According to Wikipedia, ring circuits can generate strong unwanted magnetic fields.

The alternative to a ring circuit is to use a branched /radial wiring circuit.

In a branched or radial circuit the live and neutral wires are connected to the power source at one end only, and terminate at the last socket in the circuit. The live current can take only one path – likewise the neutral current. Live and neutral current flows are always in balance, so no EMF is created.

Ring wiring circuits can generally be converted to radial circuits without large expense, but this is a job for a qualified electrician.

Checking for Home EMF

Rather Use a Qualified ElectricianIn my kitchen, lighting is by several down-lights. It was badly wired originally, which created a magnetic field of about 10 milligauss at head height, in most parts of the kitchen.


The same kind of wiring issue affecting ceiling lights on one storey can give rise to a strong EMF at floor level on the storey above.

If you are concerned about EMF from your house-wiring, it is really a good idea to obtain a suitable EMF meter to measure it.

Unless you have total confidence in your electrician, it’s difficult to know for sure whether or not your house has been properly wired to minimise EMF. Bear in mind that some electricians are not overly-concerned about EMF issues, and most do not even own a gauss meter.

It is a good idea to check any electrical work done in your house with a gauss meter, and to let the electrician know before he starts work that you would like him to check for EMFs.

Electric fields are present in live and neutral wiring, even while current is not flowing. But magnetic fields (which are thought to be more dangerous to your health) only occur when current is flowing. So when you take EMF measurements, make sure that all lighting circuits are on, and that major appliances are in use.

Trifield EMF Meter

When correcting faults, it’s best to work with an electrician who is familiar with correct and incorrect wiring practices, and how EMFs may be created.

House wiring principles apply equally to other buildings, including schools and workplaces, and it is also important that these places should be checked for EMF safety.

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You may also be interested in these articles:

EMF Protection Tips

Power Line Radiation

What Kinds of EMF are Harmful?

Who is Most at Risk?

EMF from Domestic Appliances

Low Frequency EMF Meters



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