In relation to property a group of mature students e.g. PGCEs get along fine.
Compatibility issues are likely to arise when younger and older students share a property.
Younger students are more likely to want to play loud music and want to return home late potentially disturbing their older housemates.
Discrimination on the grounds of age is allowed.
Some wisdom is required to avoid incompatibility.
Imagine a group of young girls seeking a tenant to join them. If they were unable to discriminate they might be forced to share a house with a pensioner – neither party would likely be happy with that.