As many things are in joint names the net result is your relatives end up penniless and homeless anyhow.
Errmmm...... My understanding is that a property that is held jointly as a joint tenancy (most commonly husband and wife) passes in its entirety to the surviving tenant(s) on death and does not form part of your estate. I don't know whether the same applies to other joint assets such as a bank account in joint names. Tenancy in common is different, if you are tenants in common then my understanding is that your share of the property does form part of your estate. Perhaps some legally qualified beagle can say whether I am right or wrong.