A further very full explanation of the position is given here:
There is a good summary of whether the benefit is taxable at all:
'The Revenue will accept that the ‘better performance’ test is met where:
● the employee is on call outside normal hours; and
● he is in fact called out ‘frequently’ (not defined); and
● ‘the accommodation is provided so that the employee may have quick access to the place of employment or other place to which the employee is called’ (EIM 11350 Living accommodation: practical consideration).'
It sounds from the tenor of your question that you may incur no tax liability from your occupation of the residential accommodation.
Small amendment to my original answer: line 5; delete 'loving,' insert 'living.'