EMR201 - Practical EMF Mitigation by Trade

Rob Metzinger demostrates how to measure and fix EMF issues. This is the most technical session of the summit and the most useful one if you are about to build or renovate. He works through each field type in turn, what causes it, what it reads on a meter, where government guidelines sit against building biology guidelines, and what you can actually do about it. The wiring-error section is the standout: he found two in his own new house and slept beside one for two years before he knew how to test for it.

Key Learnings

• Magnetic fields pass straight through people, walls and the earth, making them the hardest field to shield. They come from current flow: appliances, breaker panels, high-voltage wiring, wiring errors, grounding systems and copper water pipes.

• Building biology targets AC magnetic fields below 0.2–1 milligauss, while government guidelines sit at 1,000–2,000. For radio frequency, building biology targets below 0.1 microwatts per square meter, below 10 is doing well, while the government figure is 2 million–10 million.

• Two wiring errors cause most problems: neutral-to-neutral, where return current splits across multiple paths, and neutral-to-ground, where a receptacle’s neutral touches a grounded metal box and pollutes the grounding system and water pipes. One in five to two in five houses has one, including new builds, and neither shows up in a final electrical inspection.

• Stray current can come from outside. Measure the service drop with a current clamp, and clamp the gas line, water pipes and phone line because the imbalance may arrive from a neighbour.

• Wire routing matters. Larger cables carry more current and separate hot from neutral, worsening magnetic cancellation. Do not run a heavy feeder under a sleeping area, especially for anything that runs overnight.

• Specify a plug-on neutral panel. It carries hot and neutral together to the breaker, giving far better magnetic cancellation than a panel with the neutral bus six inches to a foot away.

• For radio frequency, eliminate inside sources first, hardwire the network with Cat6E or Cat7, convert Bluetooth mice and keyboards to wired, then remeasure what remains from outside.

• Shielding has rules: a full six-sided enclosure is the only certain answer. Shielding one or two sides can create reflections that raise exposure, so remeasure during and after installation. RF shielding fabric with no exposed metals survives washing.

• Low-E windows already block RF because the heat-reduction coating is sputtered metal—90–95 percent depending on the glass.

• New for 2026: magnetic-field simulation software can model the fields a design will produce before anything is built, so shielding goes in during construction rather than after.

• Location beats mitigation. A house under a power line or near a cell tower is a real-estate decision, not an engineering one.

About Rob

Rob Metzinger is an electronics engineering technologist, senior instructor at the Building Biology Institute, and founder and president of Safe Living Technologies in Canada. He started the company in 2006 and has worked full time in EMF since 2009. He is a certified building biologist, environmental consultant and electromagnetic radiation specialist, designed the Safe and Sound meter line, and co-authored a peer-reviewed paper on building science and radio frequency.

Offers

Free 15-minute consultations with the Safe Living Technologies team.
Book here: https://safelivingtechnologiescom.simplybook.me/v2/

20% off everything in the SLT store use Promo Code MYHEALTHYHOME, including meters, shielding and the tools EMF experts use.

Resources

Visit safelivingtechnologies.com. The Safe and Sound Pro 2 is the meter Rob recommends to anyone starting out, and the team answers questions on the replay page.