Rooftop Antennas and Ontario Condominiums: What Boards and Residents Need to Know

Published by Bern Management | bernmanagement.ca | August 2026

There are more cell antennas in Canada than there are Tim Hortons locations. Many sit on residential rooftops — and if you live in an Ontario condominium, the question of whether they are safe, who regulates them, and what your board can do about them has probably come up at least once in the last year.

A Note Before You Read

Bern Management is a licensed Ontario condominium property management company. We are not scientists, physicians, or lawyers. This article was produced because our clients — condo boards and residents — regularly ask us about rooftop antennas, and we could not find a single resource that addressed the question honestly, completely, and without an obvious agenda. We have tried to write that resource.

Every factual claim is sourced. Where scientific disagreement exists, we have tried to represent both sides with equal rigour. Where we have fallen short of that standard, we welcome correction.

We sent formal media inquiries to two parties before publication. We contacted Health Canada's Consumer and Clinical Radiation Protection Bureau — the specific bureau responsible for Safety Code 6 — because they are the primary regulatory authority on this question and their position deserves to be stated in their own words, not paraphrased. We contacted Dr. Paul Héroux, Associate Professor at McGill University's Faculty of Medicine, because he represents credentialed independent scientific critique of the current framework — not fringe opposition, but peer-reviewed academic dissent from within a major Canadian research institution. His perspective is directly relevant to the questions condo residents are asking.

Health Canada responded. Their reply is included in full and verbatim in Part One. Dr. Héroux had not responded as of publication. We will update the article if that changes.

This article does not constitute legal, medical, or scientific advice. Boards and residents with specific concerns should retain qualified professionals.

The honest answer takes some explaining. Health Canada and every major health authority in Canada, the United States, and Europe say that antennas operating within the approved limits do not pose a health risk to people living nearby. That position is backed by a large body of scientific research and deserves to be taken seriously.

At the same time, a smaller group of credentialed independent scientists — researchers at the University of Toronto, McGill, and elsewhere — have raised specific questions in peer-reviewed journals about whether the evidence behind that conclusion is as solid as it is sometimes presented. The legal framework, meanwhile, leaves condo boards carrying more responsibility than most of them realize.

None of this is cause for alarm. But it is worth understanding clearly — which is what this article tries to help you do.

We cover seven areas: what the regulators say, including Health Canada's direct response to our inquiry in their own words; where independent scientists see room for more scrutiny; what a Japanese condo study found and what it does and doesn't prove; the specific risk from antennas on neighbouring buildings; what the law says about a board's rights and obligations; a practical governance guide; and an honest summary of what remains unknown.

Part One: What the Regulators Say — Including Health Canada's Verbatim Reply

The basics of Safety Code 6

Canada's standard for radiofrequency exposure is called Safety Code 6, published by Health Canada. The current version is from 2015. It covers the full range of frequencies used by wireless technology — from AM radio through to 5G — and sets the maximum levels of radiofrequency energy that Canadians can be continuously exposed to.

The limits are set below the lowest level at which any proven health effect has been observed — and then pushed further down by safety margins. The standard is designed to protect everyone: children, elderly people, and people with health conditions, around the clock. (Source 1)

Putting the numbers in context

The radiofrequency levels that residents typically experience from a compliant rooftop antenna are between 0.001 and 1 microwatt per square centimetre. Safety Code 6 limits sit at roughly 200 to 1,000 microwatts per square centimetre depending on the frequency involved. That gap — hundreds to thousands of times — is important context for everything that follows.

For further perspective: using a mobile phone against your ear exposes you to significantly more radiofrequency energy than living below a compliant rooftop antenna at normal residential distances. (Source 2)

The scientific debate is about whether the limits are set correctly — not about whether most Ontario condo buildings are approaching those limits. They generally are not.

Health Canada's Response — Verbatim

When Bern Management contacted Health Canada's Consumer and Clinical Radiation Protection Bureau with questions about rooftop antenna safety in Ontario condominiums, the bureau responded. As per their request we reproduce their reply here in full, exactly as received, without any editorial alteration:

"Thank you for reaching out to Health Canada's Consumer and Clinical Radiation Protection Bureau for information about rooftop antenna safety.

Wireless devices, cell phone towers and antennas use radiofrequency (RF) electromagnetic fields (EMF) to transmit and receive information. Health Canada's mandate regarding human exposure to RF EMF is to carry out research into possible health effects, monitor the scientific literature related to such effects and to develop recommended human exposure guidelines known as Safety Code 6.

While Health Canada recommends limits for safe human exposure, Innovation, Science and Economic Development Canada (ISED) regulates wireless devices and their associated infrastructure. ISED requires compliance with the limits recommended in Safety Code 6 and conducts regular audits to help ensure wireless devices on the market and antenna installations are compliant. ISED can provide you with additional information about their requirements, as well as testing and compliance activities.

The recommended limits in Safety Code 6 are designed to provide protection for all age groups on a continuous basis (24 hours a day/seven days a week) from all scientifically established adverse health effects from exposure to RF EMF. These effects are tissue heating (like the warming of your skin) and nerve stimulation (a tingling sensation in the skin). It is Health Canada's position that the health of Canadians is protected from RF EMF when the human exposure limits recommended in Safety Code 6 are respected. If new scientific evidence were to demonstrate that exposure below recommended levels in Safety Code 6 was of concern to public health, Health Canada would take appropriate action to protect the health and safety of Canadians.

To help ensure that Canadians have access to reliable information about RF EMF and their health, the Government of Canada has addressed many commonly asked questions on its website. Below are some key webpages and resources that we recommend sharing with condominium boards and residents:

· Safety Code 6 · Radiofrequency energy and safety · Cell phones, cell phone towers and other antenna installations (includes a downloadable/printable Fact Sheet on Safety of cell phone towers and 5G technology) · Facts about towers"

— Health Canada, Consumer and Clinical Radiation Protection Bureau, 2026

Three things in this response are worth noting for residents and boards.

First, Health Canada clarifies the division of regulatory responsibility that confuses many boards: Health Canada writes the guidelines; ISED enforces them. For questions about a specific antenna installation on or near your building — compliance status, audit results, complaint process — ISED is the right agency to contact.

Second, the bureau specifies that Safety Code 6 protects against "all scientifically established adverse health effects" — which it defines as tissue heating and nerve stimulation. This is a precise statement of where the science currently stands. The independent scientists discussed in Part Two are asking whether there may be effects that have not yet met that established threshold — a specific and different question from claiming the current limits are wrong.

Third, the response includes a clear commitment: if new evidence shows a risk below the current limits, Health Canada will act. That is the regulatory framework being transparent about its own boundaries — not a fixed position, but one that moves with the science.

How regulators weigh the evidence

Health Canada uses a weight-of-evidence approach — considering both the volume and quality of research, not simply whether studies exist. Well-designed, independently replicated studies that produce consistent results carry more weight than smaller or less rigorous ones. (Source 1)

The Royal Society of Canada Expert Panel independently reviewed Safety Code 6 in 2014 and concluded that the limits adequately protect against established health effects, while recommending continued research into other potential effects. (Source 2)

The WHO classified radiofrequency electromagnetic fields as Group 2B — possibly carcinogenic in 2011. Group 2B is the lowest cancer concern category, applied when evidence in humans is limited and inconclusive. Coffee carries the same classification. It signals that more research is warranted — not that harm has been found. (Source 3)

Part Two: What Some Independent Scientists Are Asking

Good science includes ongoing scrutiny — researchers checking each other's work, questioning assumptions, and pushing for stronger evidence. That process is actively happening in the RF field, and it involves credentialed scientists whose work deserves to be understood rather than dismissed.

Who is raising questions

The International Commission on the Biological Effects of Electromagnetic Fields (ICBE-EMF) includes researchers from major institutions who have published peer-reviewed critiques of the current regulatory framework. Among them: Dr. John Frank, physician and Professor Emeritus at the University of Toronto; Dr. Joel Moskowitz of the University of California, Berkeley; Dr. Ronald Melnick, formerly of the US National Institute of Environmental Health Sciences; Prof. Lennart Hardell, a Swedish oncologist with more than 380 published papers; and Dr. Paul Héroux of McGill University.

These are not anti-technology campaigners. They are scientists using peer-reviewed methodology to ask whether the existing framework has gaps.

What the questions are — specifically

Their central concern is that the current safety limits were built around two proven physical effects of radiofrequency energy: tissue heating and nerve stimulation. Both occur at high exposure levels. These researchers argue that the limits may not adequately account for potential biological effects at lower, chronic exposure levels — the kind of long-term, everyday exposure that condo residents experience — that produce no measurable heating. (Source 4)

In 2026, a peer-reviewed paper in Environment International co-authored by Frank, Héroux, Moskowitz, Melnick, Hardell, and others argued that the WHO-commissioned review of RF-EMF research — which regulators including Health Canada rely on — has methodological weaknesses that undermine its conclusions. (Source 5)

In October 2025, the ICBE-EMF published a further analysis concluding that twelve WHO-commissioned systematic reviews on RF-EMF health effects do not reliably establish that current limits are safe. (Source 6)

To be clear about what these researchers are and are not saying: they are not claiming that rooftop antennas have been proven to harm residents. They are arguing that the body of evidence used to declare them safe has not been assembled rigorously enough to be conclusive. That is a call for better science — not a declaration of danger.

The mainstream regulatory position has not shifted in response to these critiques. The WHO has not revised the reviews in question. Safety Code 6 has not been updated. But the scientific conversation is ongoing, and it involves serious people making serious arguments.

One distinction worth understanding: hazard versus risk

These two words are often used interchangeably, but they mean different things.

A hazard is something that could potentially cause harm under some conditions. A risk is the actual likelihood of harm given real-world circumstances.

High-powered radiofrequency energy is a proven hazard — it heats tissue. The question the independent scientists are raising is whether the hazard extends to lower exposure levels than currently recognized. What they are not saying is that the real-world risk to condo residents — exposed to levels thousands of times below the regulated limit — has been established. The debate is about where the hazard threshold sits, not about whether residents are currently experiencing it.

Part Three: The Japanese Condo Study — What It Shows and What It Doesn't

One piece of research is worth examining specifically because it studied the exact situation Ontario condo residents find themselves in.

In 2014, Japanese researchers Shinjyo T. and Shinjyo A. published a study called "Significant Decrease of Clinical Symptoms after Mobile Phone Base Station Removal." They followed 107 residents of a single condominium building across three periods: before antennas were installed on the rooftop in 1998; while the antennas were operating — a second set was added in 2008; and after all antennas were removed in 2009. Residents did not know the study was connected to the antennas. The findings: reported symptoms increased when the antennas went up and decreased after they came down. The most frequently reported symptoms included fatigue, headaches, sleep problems, dizziness, and a racing heartbeat. (Source 7)

The before-and-after design gives this study more credibility than a simple survey of people who live near towers. The pattern — symptoms tracking the presence and absence of an installation in the same building, among people who didn't know that was being studied — deserves scientific attention.

That said, the study has real limitations that must be stated clearly. It involved one building in one country, with 107 people. It has not been independently replicated. Symptoms were self-reported, not clinically verified. No objective measurements confirmed how much radiofrequency energy residents were actually exposed to. And the symptoms described — fatigue, headaches, poor sleep — are extremely common and can have many causes, including stress about living near an antenna, which is a real and documented phenomenon called the nocebo effect.

This study has not changed any regulatory framework. For condo boards, the honest takeaway is: not proof of harm, but a reason to stay informed and handle antenna leases with care.

Part Four: The Risk Nobody Has Mapped — The Antenna Next Door

This is the section that surprises most people — and has the most immediate practical importance for Ontario condo boards.

Signals travel sideways, not downward

Rooftop antennas are designed to send signals outward and horizontally — toward the street and surrounding area where users are. They are not primarily aimed downward into the building below them. The strongest signal from a rooftop antenna radiates at roughly the same height as the antenna itself, spreading horizontally in the direction of the coverage area.

In a city like Toronto, Mississauga, or Ottawa — where condo towers stand side by side — this means the residents most directly in the path of a rooftop antenna's strongest signal may not be in the building that hosts the antenna. They may be in the building next door, on the upper floors that sit at exactly the height where the signal is most concentrated.

Researchers who measured radiofrequency levels in apartments near rooftop antennas found this directly. In one documented case study, where the nearest antennas were just 6 metres from a resident's balcony, 97.9% of the radiofrequency radiation detected in the apartment came from neighbouring base stations — not from antennas on their own roof. (Source 11)

The gap in protection

Safety Code 6 compliance assessments cover publicly accessible areas around the host building. The neighbouring building's residential units are private property — the carrier's engineer cannot enter them to measure, and the compliance framework does not require it. Your residents may sit in the direct horizontal broadcast path of a nearby antenna, and the current regulatory framework provides no formal mechanism specific to that scenario.

This creates a practical consideration for boards. Saying no to an antenna on your own roof does not guarantee your residents avoid all nearby exposure. It may shift the antenna to a neighbouring building where the board negotiates less carefully. A board that engages and secures strong terms — including restrictions on which direction antennas can face — may do more to protect its residents than a board that refuses and walks away from the table entirely.

What Building B's residents can actually do

Commission independent radiofrequency measurements inside your building — before and after any new installation nearby. If results approach Safety Code 6 limits, that gives you grounds for a formal ISED complaint.

ISED's consultation rules also require carriers to notify neighbouring land-use authorities within a radius of three times the tower height before an installation is approved. For a rooftop installation on a 30-storey building, that radius is approximately 270 metres and could include neighbouring condo corporations. If your board was not notified and should have been, raise that directly with ISED. (Source 12)

Part Five: The Legal Landscape — A Governance Roadmap for Ontario Boards

This is a map of the legal landscape, not legal advice. Every building's declaration is different. Before acting on anything described here, speak with a lawyer who knows Ontario condominium and telecommunications law.

You have more power than you think — but not unlimited power

A carrier needs your consent to install an antenna on your roof. Your rooftop is private property — a common element owned collectively by unit owners under the Condominium Act, 1998. No one has an automatic right to it.

The caveat: ISED's Client Procedures Circular CPC-2-0-03 includes a process that carriers can use if they believe a refusal is unreasonable — meaning a refusal without specific technical, structural, or legal grounds, not simply that owners prefer no antenna. In practice, carriers rarely pursue this against organized, well-documented board opposition. They prefer cooperative landlords.

Check your declaration first

Before any negotiation begins, confirm whether leasing the rooftop as a common element requires an owner vote under your corporation's specific declaration and bylaws. Some declarations require this. Executing a commercial lease without the required vote exposes the board to a legal challenge.

Owner votes and the precautionary principle

A documented owner vote against an antenna installation is a strong statement of the board's mandate. The board should also be able to articulate specific grounds for its decision — concerns backed by an independent RF assessment, unacceptable lease terms, or a principled application of the precautionary principle.

The precautionary principle is a recognized concept in environmental and public health law. It holds that when scientific uncertainty exists alongside potential risk, those proposing an action bear the burden of demonstrating safety — not the other way around. A board that says it is not satisfied the safety evidence is conclusive enough to justify placing continuous, involuntary radiofrequency exposure in a residential building is standing on solid ethical and legal ground.

Boards may wish to discuss with legal counsel whether citing published peer-reviewed literature — including the WHO's Group 2B classification and the ICBE-EMF's methodological critiques — could strengthen a formal refusal.

One practical step every board should demand

Whether a board says yes or no to an antenna installation, there is one requirement that should be non-negotiable if the antenna goes ahead: a post-installation compliance report.

Within 60 days of any installation, the carrier should be required — as a condition of the lease — to deliver to the corporation a Safety Code 6 compliance report signed and sealed by an independent Professional Engineer. Not the carrier's own engineer. An independent one. That report should include actual RF measurements at the rooftop, top-floor corridors, and representative residential units, expressed in microwatts per square centimetre referenced against Safety Code 6 limits. The report belongs to the corporation and should be made available to any unit owner who requests it.

This single requirement — a sealed, independent, post-installation compliance report delivered to the corporation — is absent from most standard-form antenna leases in Ontario. Its absence is the most significant governance gap in how most Ontario condo buildings currently manage this issue. Boards that negotiate it into any antenna agreement have a document they can show their residents. Boards that don't have nothing but a carrier's word.

For everything else — rent, term, renewal options, orientation restrictions, removal obligations, insurance, worker access, licence transfer, and the full range of lease terms — we strongly recommend speaking with a lawyer experienced in both Ontario condominium law and telecommunications leases before signing anything. The carrier's lease is not a neutral document. It has been refined over decades by their legal team. A lawyer who knows this territory will earn their fee many times over.

Think about the building next door

Boards that coordinate with neighbouring corporations — sharing information, RF assessment findings, and general negotiating positions — shift the balance of power significantly. A management company that applies consistent standards across its portfolio changes the dynamic entirely: carriers deal with a common framework rather than picking off buildings one at a time.

Part Six: What We Still Don't Know

The most credible thing this article can say in its closing section is what remains genuinely uncertain.

We do not know whether long-term, low-level radiofrequency exposure at the levels typical in condo buildings near compliant antennas causes any harm. The mainstream science says it does not. A credible group of researchers says the evidence supporting that conclusion needs to be built more rigorously. Both are honest positions held in good faith.

We do not know whether Safety Code 6 — last updated in 2015 — fully addresses the conditions created by today's wireless infrastructure. Most 5G frequencies fall within the ranges already covered by the code, which is a reasonable argument for its continued relevance. But the density of urban antenna installations has grown significantly since 2015, and the cumulative effect of multiple co-located arrays from different carriers on a single rooftop is not something the current framework explicitly models.

We do not know what twenty or thirty years of continuous residential exposure to today's antenna field levels produces in population health. The long-term studies needed to answer that question definitively have not been completed.

What we do know: Ontario condo residents are exposed to radiofrequency fields from nearby antennas continuously, in their own homes, with limited ability to influence the installations around them. The regulatory framework offers real protections — but it places most of the responsibility for those protections on individual condo boards negotiating one-on-one with large telecom companies. Understanding your rights and your options is not a luxury. It is part of the job.

Official Government Resources

The following links were provided directly to Bern Management by Health Canada's Consumer and Clinical Radiation Protection Bureau in response to our inquiry. They are the right starting point for any resident or board seeking authoritative information from the source.

Safety Code 6 — Health Canada's Radiofrequency Exposure Guidelines canada.ca/en/health-canada/services/health-risks-safety/radiation/occupational-exposure-regulations/safety-code-6-radiofrequency-exposure-guidelines.html

Radiofrequency Energy and Safety — ISED ised-isde.canada.ca/site/spectrum-management-telecommunications/en/safety-and-compliance/facts-about-towers/radiofrequency-energy-and-safety

Cell Phones, Cell Phone Towers and Other Antenna Installations — Health Canada (Includes a downloadable Fact Sheet on the safety of cell phone towers and 5G technology — recommended for sharing with concerned residents) canada.ca/en/health-canada/services/health-risks-safety/radiation/everyday-things-emit-radiation/cell-phones-towers.html

Facts About Towers — ISED ised-isde.canada.ca/site/spectrum-management-telecommunications/en/safety-and-compliance/facts-about-towers

Additional resources for boards:

ISED Spectrum Management System — search antenna installations by address: ic.gc.ca/engineering/SMS/

ISED Client Procedures Circular CPC-2-0-03 — the antenna approval and dispute process: ised-isde.canada.ca/site/spectrum-management-telecommunications/en/learn-more/key-documents/procedures-circulars/cpc-2-0-03-radiocommunication-and-broadcasting-antenna-systems

Health Canada — Consumer and Clinical Radiation Protection Bureau: Email: ccrpb-pcrpcc@hc-sc.gc.ca | Phone: 1-866-225-0709

A Note on What Comes Next

This article reflects the best publicly available information as of August 2026. The science of radiofrequency exposure, Canada's regulatory framework, and the pace of wireless infrastructure development are all subject to change. Readers are encouraged to check the official sources linked above for the most current government positions.

We reached out to Health Canada's Consumer and Clinical Radiation Protection Bureau and to Dr. Paul Héroux of McGill University before publication. Health Canada's verbatim response is reproduced in Part One. Dr. Héroux had not responded as of publication. If a response is received, we intend to publish it as a companion piece.

References

Health Canada. Safety Code 6: Limits of Human Exposure to Radiofrequency Electromagnetic Energy in the Frequency Range from 3 kHz to 300 GHz. Ottawa: Health Canada, 2015. canada.ca/en/health-canada/services/health-risks-safety/radiation/occupational-exposure-regulations/safety-code-6-radiofrequency-exposure-guidelines.html
Royal Society of Canada Expert Panel. A Review of Safety Code 6: Health Canada's Safety Limits for Exposure to Radiofrequency Fields. Ottawa: RSC, 2014. ISBN 978-1-927400-12-7.
International Agency for Research on Cancer. IARC Monographs, Vol. 102: Non-Ionizing Radiation, Part 2: Radiofrequency Electromagnetic Fields. Lyon: IARC/WHO, 2013.
Hardell L et al. Scientific evidence invalidates health assumptions underlying the FCC and ICNIRP exposure limit determinations for radiofrequency radiation: implications for 5G. Environmental Health. 2022;21(1):92. doi: 10.1186/s12940-022-00900-9. PubMed ID: 36081689.
Frank JW, Moskowitz JM, Melnick RL, Hardell L, Héroux P et al. The Systematic Review on RF-EMF Exposure and Cancer by Karipidis et al. (2024) has Serious Flaws that Undermine the Validity of the Study's Conclusions. Environment International. 2026;195:109200. doi: 10.1016/j.envint.2024.109200. PubMed ID: 39741032.
ICBE-EMF. The WHO-commissioned systematic reviews on health effects of radiofrequency radiation provide no assurance of safety. Environmental Health. 2025. PubMed ID: 41034851.
Shinjyo T, Shinjyo A. Significant Decrease of Clinical Symptoms after Mobile Phone Base Station Removal — An Intervention Study. Umwelt-Medizin-Gesellschaft. 2014;27(4):294–301.
Health Canada, Consumer and Clinical Radiation Protection Bureau. Response to Bern Management media inquiry regarding rooftop antenna safety in Ontario condominiums. 2026. Verbatim correspondence on file with Bern Management.
ISED. Client Procedures Circular CPC-2-0-03: Radiocommunication and Broadcasting Antenna Systems, Issue 6. Ottawa: ISED, 2022.
Infrastructure Health and Safety Association (IHSA). Exposure to Electromagnetic Radiation from Rooftop Antennas. Mississauga: IHSA. ihsa.ca
Environmental Health Trust. Apartment Cell Tower Radiation Case Report. ehtrust.org, 2017.
ISED. GL-01: Guidelines for the Measurement of Radio Frequency Fields at Frequencies from 3 kHz to 300 GHz, Issue 4. Ottawa: ISED, 2021.
ISED. GL-08: Guidelines for the Preparation of RF Exposure Compliance Reports, Issue 2. Ottawa: ISED, 2019.
Ontario. Condominium Act, 1998, SO 1998, c 19. ontario.ca/laws/statute/98c19
Canada. Radiocommunication Act, RSC 1985, c R-2. laws-lois.justice.gc.ca/eng/acts/R-2/

This article is published for informational purposes only. No part of this article may be reproduced, distributed, or transmitted in any form or by any means without the prior written permission of Bern Management. For reprint or licensing inquiries, contact info@bernmanagement.ca.

Nothing in this article constitutes legal, medical, or scientific advice. The information provided is general in nature and does not address the specific circumstances of any individual, building, or situation. Bern Management is a licensed Ontario condominium property management company, not a law firm, medical practice, or scientific authority. Readers are strongly encouraged to seek advice from qualified legal, medical, and technical professionals before making any decisions based on information contained in this article.

A Note on How This Article Was Produced

This article was researched, written, and edited by the team at Bern Management. During the drafting process, we used artificial intelligence tools to help improve clarity and flow, identify potential factual errors, stress-test our editorial positions, and ensure the article was as balanced and readable as possible. All factual claims, sourcing decisions, and editorial judgments remain our own. The verbatim response from Health Canada's Consumer and Clinical Radiation Protection Bureau is reproduced exactly as received and was not altered or processed by any AI tool. We believe in being transparent about how we work — including the tools we use.

Last reviewed: August 2026.

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