If you own you property together with someone else and this property does not constitute marital property or cohabitation property then joint ownership applies to the property, thus the Swedish Joint Ownership Act is applicable. The Joint Ownership Act includes provisions as to how you as joint owners must divide up costs for the property. By law you or one of the joint owners can also enforce compulsory sale of the property. If you do not wish these regulations to be applied you can set up a joint-ownership agreement.