Transparency Around Ontario Data Centre Development

An independent public resource.

An independent, sourced resource tracking publicly known data centre developments across Ontario, including approvals, infrastructure considerations, regulatory frameworks, and industry trends.

Rapid Expansion
C$19B announced by Microsoft for AI and cloud infrastructure in Canada, 2023 to 2027
Growing Electricity Demand
Data centres are forecast to represent about 13% of new electricity demand in Ontario by 2035 (Province of Ontario, ERO 025-1001)
Limited Public Disclosure
Ontario does not require standardized public reporting for data centre operators
No Centralized Tracking
There is no single public database consolidating publicly available data centre developments, approvals, and locations
Bill 40 Regulatory update: Ontario's draft Data Centre Playbook (ERO 026-0853) closed for public comment on September 12, 2026. The final Playbook has not yet been released, and the connection rules under Bill 40 are still being developed. Municipal councils across Ontario are taking their own action in the meantime. See the Regulatory Tracker below.
01 | The Map

Data centres across Ontario

Operational, under construction, and publicly disclosed facilities. Each entry is based on publicly available sources including ERO filings, municipal planning documents where available, and corporate or government announcements.

Legend
Sites being discussed
Application filed
Approved
Operational
Many operational entries are older colocation facilities that predate the current wave of hyperscale development. Start dates are being added as a follow-up update.
Loading… Database actively expanding.
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About these categories →

Is something missing? If you know of a data centre in Ontario not listed here, whether proposed, approved, or operational, we want to hear from you.

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Not all data centres are the same

When a new data centre is announced in Ontario, the public conversation often treats all facilities as interchangeable. They are not. A carrier hotel in downtown Toronto, a colocation campus in Markham, and a hyperscale AI facility in Vaughan have fundamentally different footprints, in electricity consumed, water drawn, and noise produced for surrounding communities.

Type 01

Carrier Hotels

Buildings where dozens of telecom companies, ISPs, and internet exchanges physically connect to each other. The value is who else is in the building, not the facility itself. Multiple independent operators can share the same address.

Power draw is distributed across many smaller tenants. Most are air-cooled. External noise impact is relatively low. 151 Front Street West was purpose-built in 1954 as a telecommunications hub, not a conversion from another use.

Ontario examples: 151 Front Street West, Toronto (operators including Equinix TR1, Cologix TOR1, Telehouse Canada, Amanah, 3Z Canada, all in the same building). TorIX operates at multiple locations including 151 Front, 45 Parliament Street, and 905 King Street West.
Type 02

Colocation Facilities

The operator provides the physical infrastructure, including the building, power, cooling, and security, while tenants bring their own servers. The operator does not control or know what runs on tenant equipment. This is the most common model in Ontario.

Power draw varies with the size of the campus. Newer facilities generally achieve better energy efficiency. Cooling varies: some use chilled water systems (higher water use), others are air-cooled. Backup generator testing can create periodic noise for neighbours.

Ontario examples: Cologix TOR4 (Markham), Csquare YYZ1 & YYZ2, Digital Realty TOR1 (Vaughan), Halton Data Center (Milton)
Type 03

Hyperscale Facilities

Built by a single company exclusively for its own use: Microsoft, Amazon, Google, Meta. Not open to other tenants. These generate the most significant public infrastructure discussions in Ontario.

A single campus can draw far more power than other facility types. Cooling approaches vary: some facilities use evaporative cooling, which consumes water, while others use air-cooled or closed-loop systems. Cooling type should be confirmed from planning documents for each site. Generator testing and cooling equipment can create a significant noise footprint.

Ontario examples: Microsoft YTO 11 (Vaughan, under construction) and Microsoft YTO 40 (Etobicoke). See the map for details. AWS, Google and others have confirmed Ontario presence but have not publicly identified specific facility locations.
Type 04

Data Centre-Ready Developments

Industrial or commercial properties built or retrofitted to the structural and electrical specifications a data centre requires, but not yet occupied by a data centre operator. A newer category emerging across the GTA.

The actual energy, water, and noise profile of these sites is entirely unknown until a tenant is confirmed and a facility type is known. “Data centre power procurement underway” is a signal that a tenant may already be committed.

Ontario examples: Prologis Meadowvale Hustler Park (Mississauga, available June 2027), Prologis Steeles Avenue Park (Brampton, available July 2027)

Environmental and community impact by type

⚡

Electricity consumption

Hyperscale (AI/cloud)Very High
Purpose-built colocationHigh
Carrier hotelModerate
DC-ready developmentUnknown

Measured by PUE (Power Usage Effectiveness). Ontario does not require operators to report PUE publicly.

💧

Water consumption

Hyperscale (liquid-cooled)Very High
Chilled-water colocationModerate
Air-cooled colocationLow
Carrier hotelMinimal

Driven by cooling technology, not facility type alone. AI chip density is the key variable. Ontario does not require water consumption reporting.

🔊

Noise impact

Hyperscale (suburban)Very High
Purpose-built colocationHigh
Carrier hotel (urban)Low
DC-ready developmentUnknown

Sources include cooling equipment and backup generator testing. Municipal noise by-laws apply but continuous low-frequency industrial noise is difficult to enforce.

What operators disclose, and what they don't

Information Availability Notes
Power capacity (MW) Inconsistent Some operators publish capacity in marketing materials. For several sites this tracker follows, no MW figure appears in any public planning document.
PUE (energy efficiency) Sometimes public Published by some operators in sustainability reports, usually at company or regional level, rarely per building
Actual electricity consumption Not public No Ontario requirement to report consumption by facility.
WUE / water consumption Rarely public Where available, figures typically come from municipal planning filings rather than operator disclosure. No Ontario reporting requirement exists.
Cooling technology type Sometimes public Larger operators often reference air vs. water cooling in spec sheets or sustainability reports
Certifications (LEED, ISO, Uptime) Typically public Operators market certifications; independently verifiable through certifying bodies
Carbon emissions Rarely public Some large operators publish Scope 1/2/3 at corporate level. Per-facility figures are almost never disclosed in Ontario
Noise assessments Sometimes public May appear in municipal planning filings or environmental assessments if required. Not consistently available

This tracker cites figures where operators have voluntarily disclosed them, and clearly states when information is not publicly available. The goal is not to fill gaps with estimates but to make the gaps themselves visible. Residents, municipalities, and policymakers deserve to know what they are, and are not, being told. Read the full explainer in Updates →

03 | Regulatory Tracker

The regulatory landscape

What exists, what is proposed, and where accountability gaps remain. Each item is tagged by status.

In force, regulations pending

Bill 40: Electricity Act amendments

Bill 40 (Protect Ontario by Securing Affordable Energy for Generations Act, 2025) received Royal Assent on December 11, 2025. It adds section 28.1 to the Electricity Act, 1998, which prohibits transmitters and distributors from connecting a "specified load facility," including a data centre that meets criteria set by regulation, unless connection requirements specified in regulation are met.

The Act leaves the key details to regulation, which is made by the Lieutenant Governor in Council. That includes how "data centre" is defined, what size or location thresholds apply, what approvals are required, and who grants them. The Act permits those requirements to include criteria related to economic development and job creation.

Section 28.1 does not apply to a facility whose connection request was submitted to a transmitter or distributor before June 3, 2025.

Bill 40 also adds economic growth to the objectives of the IESO and the Ontario Energy Board.

The Act itself does not create reporting or disclosure obligations for data centre operators.

Electricity Act, 1998, as amended by Bill 40, SO 2025, c. 22

Proposed, consultation closed

Ontario Data Centre Playbook (ERO 026-0853)

Released August 13, 2026 as a draft for public comment. The Playbook proposes assessing new data centres against three provincial priorities (advancing economic development, protecting data security and digital sovereignty, and investing in communities and earning public confidence) to inform grid connection approvals. It also proposes a separate electricity rate class for large new data centres. The comment period closed September 12, 2026. The Province has said a final Playbook will follow alongside its AI Industrial Strategy.

The Playbook addresses grid connection. It does not address municipal land-use planning or zoning approvals.

Environmental Registry of Ontario, ERO 026-0853

Voluntary

Federal Responsible Data Centre Development Principles

Announced by the Government of Canada on September 3, 2026. The principles set five expectations: data centres must create lasting local benefits, must not shift electricity costs to Canadians, must minimize water use and environmental impacts, must be transparent about local impacts, and must bring strategic value to Canada. They are principles, not regulation, and include no enforcement mechanism.

Government of Canada, September 3, 2026

Municipal sector position

AMO submission on the Playbook

On September 11, 2026, the Association of Municipalities of Ontario (AMO) submitted "Balanced Priorities, Local Benefits: A Framework for Data Centre Development" to the Playbook consultation. Its five recommendations include a collaborative review process involving the Province, municipalities, and Indigenous communities, and a commitment to maintaining full municipal planning and development approvals.

Association of Municipalities of Ontario, September 11, 2026

Local action

What municipalities are doing

With no provincial land-use framework for data centres, some Ontario councils have acted on their own. Examples include:

  • Oakville: passed a one-year interim control by-law (By-law 2026-129) on August 11, 2026 (Source)
  • Mississauga: council passed an interim control by-law on September 16, 2026, pausing new data centres and similar facilities with a peak power demand of 10 MW or more for up to one year (Source)
  • Sault Ste. Marie: on September 21, 2026, council approved a draft municipal framework that proposes requiring a rezoning for any data centre of 5 MW or more, and passed an interim control by-law restricting data centres for up to one year while the framework is finalized (reported by the Sault Star; minutes pending). Public consultation is expected to run until early 2027.
  • Hamilton: a proposed interim control by-law was defeated 10-6 on July 15, 2026 (Source)
  • Chatham-Kent: council directed staff on September 21, 2026 to report on the scope of a potential study of AI data centres, including the use of an interim control by-law, with a report expected in December 2026 (Source)
Gaps

What is not standardized province-wide

  • A public registry of proposed, approved, or operating data centres
  • Mandatory reporting of electricity or water consumption
  • Disclosure of facility electrical capacity in planning applications
  • A land-use or zoning framework specific to data centres
  • Public tracking of operator commitments after grid connection
Section 04 | Key Questions

Questions about Ontario's data centre and energy system

These questions identify areas where public information is incomplete or evolving. This section is updated as new information becomes available.

05 | Updates & Analysis

Latest updates

Regulatory developments, facility announcements, best practices from other jurisdictions, and community impact reporting. Updated as news develops.

06 | Plain Language Definitions

Plain Language Definitions

Simple explanations of key terms used in discussions about Ontario data centres, AI infrastructure, and electricity planning.

What is a Data Centre?
🖥️Data centre
A large building filled with computers that store data, run applications, and support services like cloud computing and artificial intelligence. They require significant electricity and cooling infrastructure.
🏗️Hyperscale data centre
A very large data centre built by a major technology company for its own use. These facilities operate at massive scale and require significant electricity, water, and infrastructure investment.
☁️Cloud computing
Using computing services like storage, software, and processing over the internet instead of on a personal device or local server. Data centres are the physical infrastructure that makes cloud computing possible.
🤖AI compute
The computing power needed to build and run artificial intelligence systems. AI applications place significant demand on data centre infrastructure, driving much of the current expansion in Ontario.
AI Basics
🏋️Training vs. inference
Training is when an AI system is built using large amounts of data: computationally intensive and high energy. Inference is when the trained AI responds to questions or performs tasks. Inference uses less energy per request but happens far more often, and at scale can exceed training demand.
Electricity System
🔌Electricity grid
The network that delivers electricity across Ontario from power plants to homes and businesses. Large data centres place significant new demand on the grid and may require infrastructure upgrades to connect.
📊Electricity demand (load)
The total amount of electricity being used at a given time. Large data centres can significantly increase local and provincial demand. The Province forecasts data centres will represent about 13% of new electricity demand by 2035.
🔗Grid connection
Approval to connect a facility to Ontario's electricity system so it can draw power. Under Bill 40, large data centres will need to meet connection requirements set by regulation before a transmitter or distributor can connect them.
⚡Megawatt (MW)
A unit of electrical power. A data centre's capacity is usually stated in megawatts, and figures range widely by facility type and size. The energy a facility actually uses over time is measured in megawatt-hours (MWh): 1 MW used for one hour equals 1 MWh. Ontario does not require data centres to publicly disclose either figure.
🔀Transmission vs. distribution
Transmission refers to high-voltage lines that move electricity across long distances. Distribution refers to the local lines operated by utilities that deliver electricity to homes and businesses. Larger data centres may connect at the transmission level, while smaller facilities typically connect to a local distribution system. Bill 40 applies to both.
Planning & Development
📍Zoning
Municipal rules that determine what types of buildings or uses are allowed on a piece of land. Data centres require appropriate zoning approval from the local municipality before construction can begin.
🏢Site plan approval
A municipal review process that determines how a building is designed and built on a site, including access, landscaping, and servicing. A step in local planning approval for data centre development.
🧭Infrastructure load
The total demand a development places on systems like electricity, water, and transportation. Data centres place concentrated infrastructure load that communities and utilities must plan for.
Water & Environment
💧Direct vs. indirect water use
Direct water use is what a data centre uses on-site for cooling. Indirect water use is consumed at the power plants generating the facility's electricity. Operators typically report direct consumption only. Researchers note indirect consumption can be significantly higher at scale.
🌿Environmental Registry of Ontario (ERO)
A public website where proposed government policies and regulations are posted for public comment. ERO postings are a primary source for tracking data centre-related regulatory activity in Ontario.
Policy & Regulation
📜Legislation vs. regulation
Legislation refers to laws passed by government, such as Bill 40. Regulations are the detailed rules that explain how those laws are applied in practice. Regulations are created after legislation passes and fill in the operational details.
🔑Connection approval
Bill 40 allows regulations to require an approval before certain data centres can connect to the grid, and to specify who grants it. The Act itself does not name the approver. The draft Playbook describes a provincial assessment process. This is a grid access decision and does not create ongoing reporting obligations once a facility is connected.
🌐Data sovereignty
The principle that data is subject to the laws of the country where it is stored. Building Canadian data centre capacity means Canadian data stays in Canada, subject to Canadian privacy law, rather than being stored on foreign infrastructure.

Submit a tip or correction

This tracker is only as accurate and complete as the information available to us. We actively welcome tips, corrections, source documents, and facility information from residents, municipal staff, journalists, and industry insiders.

All submissions are reviewed before being incorporated. We do not publish the names of people who send us information unless they ask to be credited.

A data centre not listed on the map
A council decision or motion on data centres
A factual error in a facility profile
A regulatory update or new ERO filing
A public commitment not reflected here
Community impact information we should know about

Name and email are optional. Submissions are sent through Formspree, a US-based form service, to our editorial inbox at ontariodatacentres@gmail.com. We do not publish the names of people who send us information unless they ask to be credited. Please do not include personal details about other people.