Changing Co-ownership Shares in Quebec

In Quebec, co-ownership shares determine the relative value of each fraction in a divided co-ownership. They influence voting rights, the allocation of common expenses and condo fees, as well as contributions to the contingency fund. When the reality of the building changes, it may become necessary to adjust these shares. (Updated as of 2026-05-20.)

Looking for answers about “changing co-ownership shares in Quebec”? Here is a clear guide to help you decide whether a review is necessary, understand the legal requirements and structure a process that reduces the risk of conflict among co-owners.

For structured administrative support, see our management services on the multiRent Services page: administrative management and financial management.

Why and when to change co-ownership shares

Changing co-ownership shares is not a minor step. It affects every co-owner’s finances and the balance of the divided co-ownership. However, several situations may justify it:

• Major alterations to a private portion (e.g., a mezzanine added or an expansion authorized by the by-laws and the board of directors).
• Changes to the building that affect the relative use or appeal of certain fractions (e.g., enclosing a common terrace or adding an elevator).
• The division or consolidation of fractions as part of an approved major renovation.
• Errors or inconsistencies identified in the original declaration of co-ownership (e.g., incorrect areas or inequitable coefficients).
• An authorized change of use that changes the purpose and relative value (e.g., a change from residential to mixed use, depending on the declaration of co-ownership and municipal permits).

Before undertaking a review, the board of directors should document the need factually (photos, plans, authorizations and relevant minutes) and determine whether a simpler solution would be sufficient (e.g., correcting an inaccurate description of the private portions without changing the relative value). A review by an appraiser or notary can confirm whether the discrepancy identified really justifies changing the co-ownership shares.

Quebec legal framework: declaration of co-ownership, votes and publication

In Quebec, each fraction’s share is set out in the declaration of co-ownership and is used, among other things, to calculate contributions to common expenses and the contingency fund. The Civil Code of Quebec requires each co-owner to contribute in proportion to the relative value of their fraction (see section 1064 C.C.Q.; see the Civil Code on LégisQuébec). Changing these values means changing the declaration of co-ownership itself.

In practice:

• Changing the relative value (the co-ownership shares) is a substantial amendment to the constituting act of the divided co-ownership. It generally requires the unanimous consent of the co-owners, unless a court decision imposes it in the event of a deadlock or a clear irregularity.
• Other changes to the declaration of co-ownership may require different qualified majorities, but any amendment affecting the allocation of common expenses and voting rights tends to involve high requirements. The board of directors must plan the meeting strategy based on the thresholds set out in the Civil Code of Quebec and the declaration of co-ownership (see the provisions on assembly decisions, sections 1096 and following of the C.C.Q.).
• The adopted amendment must be received by a notary and published in the land register to be enforceable against third parties. Without publication, the amendment remains ineffective against purchasers and creditors.

To consult the rules on contributions and assembly decisions:

• Civil Code of Quebec — Co-ownership by fractions (LégisQuébec):
  • Contribution to common expenses (see section 1064): text of the Civil Code
  • Provisions on assembly decisions: relevant section of the Code
• Practical resources are also available from the RGCQ (best practices) and the OACIQ for impacts during a sale and information that must be disclosed.

How to recalculate: method, expert and criteria

The method for calculating co-ownership shares is intended to reflect the relative value of each fraction. It is based on objective criteria and a consistent weighting scale. A rigorous approach reduces challenges.

Good calculation practices:

• Give the mandate to an independent chartered appraiser. Their report justifies the coefficients and the overall fairness of the result.
• Use measurable parameters: net area of the private portions, floor, orientation, fenestration, noise, views, presence of a balcony, indoor/outdoor parking, access to an elevator, etc.
• Apply transparent coefficients: for example, +X% for a higher floor with an unobstructed view, -Y% for increased noise. The percentages must remain justifiable and documented.
• Clearly distinguish private portions from exclusive-use rights over common portions (terrace, outdoor parking). Exclusive-use rights may influence relative value, but they are not private-portion areas.
• Test the overall impact: the sum of the co-ownership shares must equal 100%. Check that two comparable fractions receive similar values.

The appraiser’s report will be the key document for informing co-owners, preparing the notice of meeting and drafting the proposed amendment to the declaration of co-ownership. It will be appended to the minutes of the assembly that adopts the amendment.

Administrative steps for the board of directors and syndicate

The board of directors must oversee a formal, traceable process. The following is a recommended action plan:

1. Preliminary analysis by the board of directors

   • List the reasons and supporting documents (plans, permits, minutes, area measurements, photos, statement of condition/maintenance logbook as needed).
   • Review the declaration of co-ownership to confirm the amendment rules and voting thresholds.

2. Mandate to an expert

   • Select an independent chartered appraiser and clearly define the scope of the mandate.
   • Receive a detailed report with the new relative-value table and methodology.

3. Legal preparation

   • Have a notary prepare a proposed amendment to the constituting act of the declaration of co-ownership, including the new co-ownership share table.
   • Review the wording to ensure that no other clause is affected as a result.

4. Notice of meeting

   • Hold an annual general meeting or special meeting, with a notice detailing the purpose, impacts and documents (the report and proposed amendment) made available in advance.
   • Comply with the rules on notice of meeting, quorum and voting. State the resolution precisely.

5. Holding the vote and preparing the minutes

   • Record the result, objections and abstentions accurately in the minutes.
   • Obtain, where required, the individual signatures of the co-owners for unanimity.

6. Signing and publication

   • Sign the notarized amendment.
   • Publish it in the land register. Update the co-ownership register and the unit records.

7. Financial implementation and communication

   • Adjust the budget, statements of account and allocation key for common expenses and the contingency fund as of the effective date decided.
   • Inform each co-owner of their new contribution. Update the syndicate’s certificate provided during a sale.

To structure these steps, also consult our Services section — operations management. You can browse other topics on the blog page.

Impacts on common expenses, the budget and communications

The new co-ownership shares change the allocation of contributions. Some units will pay a little more, while others will pay a little less. The goal is not to “win” or “lose”, but to reflect relative value fairly.

Financial points to watch:

• Current budget: choose a clear effective date (e.g., the first day of a month) to avoid a complex calculation in the middle of a period. Record it in the minutes.
• Arrears and credits: provide a simple mechanism to adjust an overpayment or balance owing if the effective date occurs after calls for funds have already been sent.
• Contingency fund: the allocation key also changes. Check the impact on annual contributions and any potential special assessments.
• Syndicate certificate and sales: inform brokers and notaries that the revision is in effect. The OACIQ reminds us of the importance of disclosing relevant information during a transaction.

For communications, focus on education: explain the method, provide simple examples with figures and publish the documents in the co-ownership register. A summary page accessible to co-owners reduces misunderstandings.

FAQ — Frequently asked questions

Can co-ownership shares be changed without unanimity?

Generally, no. Because co-ownership shares affect fundamental rights and obligations, the unanimous consent of the co-owners is usually required. In the event of abuse, an obvious error or a deadlock, an application to the court may be considered to have an equitable solution approved, depending on the principles of the C.C.Q. and the evidence submitted.

Who pays the costs associated with the review?

The expenses (appraiser, notary and publication) are common expenses, unless the declaration of co-ownership provides otherwise or an agreement is adopted by vote. The board of directors should budget for these costs and inform the co-owners in the notice of meeting and minutes.

Do areas have to be certified?

Ideally, yes. Compliant measurements and a consistent methodology strengthen the credibility of the new scale. A chartered appraiser will use best practices; this also facilitates acceptance at the assembly and among purchasers.

Useful resources:

• Civil Code of Quebec – Co-ownership by fractions (general rules and assembly decisions): LégisQuébec
• Proportional contribution to common expenses (see section 1064): Code text
• Best practices in co-ownership: RGCQ
• Brokerage and disclosure when selling a condo: OACIQ

This article provides general information and does not constitute legal advice. Consult a lawyer or notary regarding your situation.

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