The agreement allows you to choose the ownership shares or make arrangements to change the shares. For example, you may want a gradual increase from a homeowner who pays a mortgage or a parent lender. Co-ownership contract: holiday properties govern the common ownership and use of a house, apartment or other real estate for the occupation of holidays between different owners The cohabitation agreement defines housing conditions, such as for example. B responsibility for invoices. Depending on your relationship, you may also want to consider a binding financial agreement or separation agreement to determine ownership of other assets. . . .