Living Near Hydro Towers in Markham: What the Science Says About EMF and Your Home

The house checks every box. Then a buyer looks out the back window and sees a steel tower against the sky. The room goes quiet. Someone pulls out an EMF meter. The showing is over in ten minutes.

This happens more often than you might think in Markham, where Hydro One corridors run behind some streets. Concern is real, and it deserves a real answer. This guide covers what the research says, what an EMF reading actually means, and how a tower can affect price.

Michael John Lau is one of Markham's top real estate agents, with 430+ homes sold, a 5.0 rating across 81 Google reviews, and eXp ICON Agent awards in 2024 and 2025. He has walked many buyers through homes near hydro corridors, and helped sellers price and market them well. This is the plain-language summary he shares, based on Health Canada and WHO findings. It is general information, not medical advice.

What is EMF from hydro towers?

Every wire carrying electricity creates an electric field and a magnetic field. Power lines, house wiring and appliances all give off extremely low frequency (ELF) fields at 60 Hz. This is different from the radio-frequency energy from cell towers, Wi-Fi or microwaves.

Electric fields are easily blocked by walls, trees and roofs. Magnetic fields pass through walls, but they get weaker very quickly as you move away from the source. That is why distance matters more than anything else.

Is it harmful to live near hydro towers? What the studies say

Here is what the main health authorities have concluded:

• Health Canada says there is no conclusive evidence of harm from EMF at levels found in Canadian homes and schools, including areas just outside power line corridors. It does not consider any precautions necessary for daily exposure.
• The International Agency for Research on Cancer (IARC), part of the WHO, classified ELF magnetic fields as "possibly carcinogenic to humans" (Group 2B) in 2002. This was based on limited evidence for childhood leukaemia.
• The World Health Organization reviewed the research in 2007. Pooled studies found about double the childhood leukaemia risk in homes with average magnetic fields above 0.3 to 0.4 µT (3 to 4 mG). But the WHO said the evidence is not strong enough to be considered causal, pointing to possible study bias, no known biological mechanism and mostly negative animal studies.
• For other conditions, such as adult cancers, heart disease and breast cancer, the WHO found the evidence much weaker, or found that the fields do not cause them.

Group 2B is a cautious category. It means scientists cannot rule something out, not that it has been shown to cause harm. Most homes, even near corridors, sit well below the 3 to 4 mG range once you are a few hundred feet away.

This is general information, not medical advice. If you have a specific health concern, speak with your doctor.

How far from a hydro tower is far enough?

The table above shows published averages for a 230 kV line. By about 200 feet, the field is in the same range as an average North American home. Real readings depend on the line's voltage, how much power it is carrying at that moment, and the tower design.

For perspective, Hydro One lists household appliances measured at 6 inches: a microwave around 200 mG, a vacuum around 300 mG, and a refrigerator around 2 mG. Standing at your stove or vacuuming can expose you to a higher field, for a short time, than a backyard near the corridor.

Should you use an EMF meter at a showing?

You can, and some buyers in Markham do. A reading can give peace of mind. Keep these points in mind so the number is useful:

1. Use the right meter. Power lines produce ELF magnetic fields, measured in milligauss (mG) or microtesla (µT). Many low-cost meters mainly measure radio frequency from Wi-Fi and phones, which is a different thing.
2. Measure in several spots. Check the bedrooms, the main living area and the backyard. Also take a reading away from appliances, wiring panels and chargers, which can spike numbers.
3. Measure more than once. Line loads change through the day and with the seasons. A hot summer afternoon can read higher than a mild morning.
4. Compare to context. Hold the meter near your own fridge or microwave at home. It helps you judge what a reading really means.
5. Ask the utility. Hydro One publishes EMF information and can answer questions about lines near a property.

Please ask permission before taking measurements in someone else's home. Most sellers are happy to allow it.

Do hydro towers lower home values in Markham?

Often, yes. This is the effect with the strongest evidence. A well-known Canadian study of 507 house sales in Brossard, Quebec found that a direct view of a pylon or wires lowered prices by about 5% to well over 20%. The same study found that simply backing onto a corridor did not always hurt value. Some homes sold for a premium because of the open space and privacy.

That matches what agents see in the GTA. Many buyers filter out these homes, which shrinks the buyer pool and can lengthen time on market. Others see a value: a larger lot, no rear neighbours, and green space that will never be built on.

For buyers, a home near a corridor can mean more house for the money. For sellers, it means pricing and presentation need extra care.

Buying a home near a hydro corridor: a simple checklist

• Measure the distance from the home to the actual wires, not just the tower.
• Check where the bedrooms and outdoor living space face.
• Listen for buzzing on a humid day. Some lines hum, which matters more to some people than EMF.
• Look at recent sales near the corridor versus a few streets away.
• Ask what the corridor is used for. Many host trails or open space.
• Think about resale. The next buyer may have the same concern you do.

Ready to compare homes? See how buyer representation with Michael works, or browse the Markham neighbourhood guide.

Selling a home near hydro towers in Markham

Do not hide it. Buyers will see the towers in photos, maps and on the drive in. Address it early and with facts.

• Price with the right comparables: use sales near corridors, not only the best streets in the neighbourhood.
• Market the benefits: no rear neighbours, open views, a quiet trail or a deeper lot.
• Have answers ready: share the Health Canada and WHO facts, and be open to buyers taking EMF readings.
• Listen to feedback: adjust quickly if showings stall.

A good example of this approach is 278 Williamson Road. That home faced a different objection, a main road and a school across the street. By listening to showing feedback and repositioning the home, it sold within 12 days. The same thinking applies to a corridor lot.

Thinking of selling? Start with a free home evaluation in Markham.

Frequently asked questions

Is it safe to live near hydro towers in Canada?

Health Canada says there is no conclusive evidence of harm from EMF at levels found in Canadian homes, including just outside power line corridors, and it does not consider precautions necessary. Research continues, and the WHO recommends ongoing study.

Do power lines cause cancer?

The WHO's cancer agency classifies power-frequency magnetic fields as possibly carcinogenic, based on a weak link with childhood leukaemia at average exposures above 0.3 to 0.4 microtesla. The WHO says the evidence is not strong enough to show the fields cause it.

How far should a house be from power lines?

There is no official safe distance in Canada because Health Canada does not consider precautions necessary. For a typical 230 kV line, magnetic fields drop to around normal household levels by about 200 feet.

What EMF reading is normal in a home?

The WHO reports average home magnetic fields of about 0.11 microtesla (about 1.1 mG) in North America. Readings rise near appliances and wiring and fall quickly with distance.

Do houses near hydro towers sell for less?

Often. A Canadian study in Brossard, Quebec found a direct view of a pylon or wires reduced prices by about 5% to over 20%. Homes that simply back onto a corridor do not always sell for less, especially when buyers value the open space.

Can buyers bring an EMF meter to a showing?

Many sellers allow it if buyers ask first. Use a meter that measures low-frequency magnetic fields in milligauss or microtesla, and take readings in several rooms and at different times.

Keep reading

Sources

• Health Canada: Electric and magnetic fields fact sheet (via Hydro One)
• World Health Organization: Fact sheet 322, ELF fields (2007)
• Hydro One: Electric and magnetic fields
• Dominion Energy: Typical EMF levels for transmission lines
• Des Rosiers (2002): Power lines, visual encumbrance and house values, Journal of Real Estate Research

Information is accurate to the best of our knowledge as of October 7, 2026 and may change. Not intended to solicit buyers or sellers currently under contract.