Large & Special Purpose Property Engagement Plans Supporting the 2020 Assessment Update

NOTICE: We have cancelled our large and special purpose engagement session scheduled for Thursday, March 19. We remain committed to our engagement activities and will be sharing more information on a rescheduled session date in the near future.  

MPAC assesses all properties in Ontario every four years. For the 2020 Assessment Update, we will be engaging with large and special purpose property owners, affected municipalities and other stakeholders as part of our work to determine updated assessments for these properties across the province.

Our engagement process will focus on bringing property owners, municipalities and stakeholders together with our assessors to:

  • Improve data collection;
  • Consult and collaborate on valuation methodologies and key valuation parameters;
  • Identify areas of risk within each respective industry; and,
  • Share preliminary values with property owners and municipalities to identify any concerns before roll return in December 2020.

Sectors included in the Large & Special Purpose Category

Our engagement will include all resource-based plants and those large manufacturing plants that are designed for a special purpose.

For large manufacturing plants to be considered large and special purpose, they must meet additional objective property related criteria as outlined below:

All resource-based plants Criteria

Pulp & Paper Mills

Saw Mills

Value-Added Wood Products Manufacturing Plants


Oil Refineries

All properties within these sectors are included

Large Manufacturing Plants Criteria

Aerospace Product Manufacturing Plants
Automotive Assembly Plants
Automotive Parts Manufacturing Plants
Chemical Manufacturing Plants
Steel Manufacturing Plants

Properties that fall within one of these sectors and meet the following criteria are included:

  • 125,000 square feet or more; and
  • 20 or more buildings*;
  • or more than 250,000 square feet (without regard for the number of buildings)

Food Manufacturing Plants

Properties that fall within this sector must be:

  • 125,000 square feet or more

Pharmaceutical Manufacturing Plants

Properties that fall within this sector must be:

  • 125,000 square feet or more

Stakeholder Engagement

Why it is important to participate in engagement activities?

Active participation in the engagement process is important for property owners, municipalities and other stakeholders, as the assessment methodology and key market parameters discussed will inform the basis of updated property values that will be in place for the 2021-2024 property tax years.

How can you participate in engagement activities?

Providing opportunities for meaningful engagement and information sharing is our focus - and we have developed a four-stage approach:






Property owner receives Assessor's Letter of Intent from MPAC.

Property owner and municipality receive formal information request.

Market valuation parameter forums begin.

Market valuation parameter forums continue to discuss preliminary property values.

Property owner receives Property Assessment Notice from MPAC.

The letter will explain the engagement process, explain what to expect and define which property types will be taking part.

Formal information requests will be sent to all large and special purpose property owners as well as affected municipalities, in order to help ensure we have the most accurate and up-to-date information for analysis and consideration.

The first of two market valuation parameter forums will start in fall 2019: interactive sessions focused on sharing and exchanging information to support the development of key valuation parameters to support the valuation process.

Once we receive information and input, we will develop preliminary values to share and consult on beginning in June 2020.

The updated assessed value shown on your Property Assessment Notice will be used to calculate property taxes for the 2021-2024 property tax years.

Invitation: large and special purpose engagement

Information and Data Sharing Policy

The Information and Data Sharing Policy applies to all industrial, commercial and multi-residential properties.

This Policy is intended to provide clarity regarding the type of information and data that assessed persons, representatives, municipalities and other parties need to provide MPAC for any purpose relating to the assessment of land.

Questions or comments?

Please send an email to if you have any questions or comments. Check this page regularly for updates as the 2020 engagement process continues.

Note: The applicable law prevails to the extent there is any conflict between this information and the current law. This information is not intended to provide legal advice and should not be relied upon as such.