If one owner wants to sell and the other doesn't, Ontario's Partition Act lets the willing owner ask the Superior Court of Justice to order a sale of the property. Judges grant those orders in most cases, because getting out of shared ownership is treated as a right, not a favour that the other owner can withhold.
The authority comes from the Partition Act, R.S.O. 1990, c. P.4. Section 2 lets any person with an interest in land in Ontario bring an action or application for partition or sale, and section 3 extends that to joint tenants and tenants in common. Partition means physically dividing the land, which rarely suits a house or a condo, so the usual outcome is a sale with the net proceeds split by each owner's share.
Ontario courts describe this as a prima facie right. The owner who wants to sell does not have to prove the sale is sensible or well timed. The burden sits with the owner resisting it, and the grounds that succeed are narrow. Judges have refused to order a sale where the application was malicious, vexatious or oppressive, or where a related claim such as unjust enrichment had to be decided first. Unhappiness about the market is not a defence.
How title is held changes less than people expect, since both forms of co-ownership carry the same right to apply. What it does change is what an owner can do alone. A tenant in common may transfer their own undivided share without anyone's consent, though buyers for a partial interest in a home are scarce. Anyone weighing this should understand joint tenancy versus tenancy in common before signing.
Married spouses sit outside all of this. Section 21 of the Family Law Act says no spouse may dispose of or encumber an interest in a matrimonial home without the other spouse's consent or a court order, regardless of whose name appears on title, and those disputes travel through family court with the rest of the property division. The same is true when a marriage ends and the house is in play.
Very few of these standoffs reach a hearing. Once an application is filed, the resisting owner is often better off buying the other share at an appraised value, and litigation costs give both sides a reason to settle. A co-ownership agreement written before the purchase, which is why buying with a friend works best with an exit plan, avoids the court route entirely.
Related reading: Joint Tenancy vs Tenancy in Common in Ontario, Can You Buy a House With a Friend in Ontario?, and What Happens to the House in a Divorce in Ontario?.
