The rights and responsibilities of common owners can vary greatly by the type of ownership of property they bare. In real estate property, there are laws that relate to each type, and are important for both owners to be aware of. The different types of ownership common owners can get into have different requirements or criteria, that must be met in order for such an ownership to take place. Once a common ownership is established, then the two parties must abide by all the rights and responsibilities that come along with that ownership.
In a co-ownership, the two owners are responsible for any costs associated with the ownership of that property. These costs can vary from maintenance to certain utilities ( as previously determined), mortgage payments, etc. The owners are not mandated to make payments on any repairs or improvement on the property in order to raise its value. However, some common owners do sign a written agreement that can pertain to these costs prior to ownership, or during ownership, if they choose to collectively repair/improve something on the property.
If one of the owners chooses to upgrade the property at their cost, they of course cannot ask the other owner to contribute for their upgrade even if it raised the value of the house. Now, during a partition, the other owner can seek to recuperate the funds if the property is sold at a higher value due to the upgrades.
The problem with an owner choosing to make an upgrade though, is that they do so at a risk. Should the property not increase in value, then they will not be able to recover any of the costs they spent on such upgrades. Additionally, if the property value is subsequently decreased because of the attempted upgrade or improvement, then that owner will have to make up the lost amount with their co owner. Common owners can restrict the other owner's share on a property by taking out a mortgage on that share. However, there must be an entitlement to fair dealing. This means that the owner taking out the mortgage must give his co-owner a chance to purchase pro rata shares of that mortgage.
Within the basic rights that common owners share is the right of access. Both owners share an equal access to the property, completely unrestricted. Any restrictions of one owner over the other can result in a cause for 'ouster.' In this case, the owner that was denied access to the property is subject to recover funds for his time lost in the form of rental value of the property over that time.
Common ownership is popular among people looking to share the cost of a property to live together, as a means to not 'throw away' money on rent, or to use as a rental unit where both owners would make an income off that rent. Regardless, common owners have the opportunity to split an investment to lower the costs of a single person, by dividing in two, and sharing the responsibilities that come with the territory. If you need legal advice and assistance, contact real estate lawyers.