Can matrimonial home protections be waived in advance through a marriage contract in Ontario?

No, at least not for the core protections around consent to sell and equal possession. Ontario's Family Law Act specifically provides that a term in a domestic contract, including a marriage contract signed before or during a marriage, cannot limit a spouse's rights under the matrimonial home provisions, and any attempt to do so is unenforceable. This is different from most other property rights, which spouses generally can contract around freely, and reflects a policy choice that the right to live in, and have a say over disposing of, the family home shouldn't be something a spouse can sign away in advance.

This means a clause in a prenuptial agreement stating that one spouse waives their matrimonial home rights, or agrees in advance that their consent won't be needed to sell it, generally won't hold up if challenged later, even if both parties signed it willingly with legal advice at the time. Couples can still address most other financial and property matters comprehensively in a marriage contract; this particular carve-out is narrow but firm. Anyone drafting or relying on a marriage contract that touches on the family home should get advice specifically on this limit, rather than assuming a clearly worded waiver will be effective.