A tenant must not make any alterations or additions, or add fixtures, to a property without the written permission of the owner.
If damage is caused by a tenant making alterations – even where the tenant has permission – the tenant should notify the owner as soon as possible. The owner may allow the tenant to repair the damage or request compensation for reasonable costs of repairing the damage.
If alterations, additions or fixtures are made during the tenancy without permission and the owner wishes to remove them at the end of the lease, the tenant will be responsible for the cost. A common example is satellite dishes on the roof.