In short
Can I sell our house without my ex's agreement?
You cannot simply sell the property on your own, but you also cannot force your ex to remain co-owner. In Belgium, no one can be forced to stay in undivided co-ownership. If your ex refuses to sell or buy you out, you can have the division enforced through the family court, with a judicial or public sale as the final step.
As long as you both own the property, you generally need your ex's agreement to sell. But if talks stall, you are not powerless. Belgian law states that no one can be forced to remain in undivided co-ownership (Article 4.66 of the Civil Code, formerly the well-known Article 815). You can therefore demand the division of the property at any time.
Concretely, you ask the family court to order the liquidation and division. The court then appoints a notary-liquidator to manage the case. If the property cannot be divided in kind, which is almost always the case with a house, the sale can be ordered so that the proceeds are divided. This is a legal process, so have your own lawyer or notary assist you.



