Illustrative example
A council inspection of a rented terraced house records a serious hazard for damp and mould growth. The tenant sends the report to the landlord, who replies that a council rating is a matter between him and the council and has nothing to do with the tenancy.
Section 10 imposes no duty on anyone - it supplies the test that sections 8 and 9A depend on - and for a dwelling in England it expressly brings in the hazards prescribed under the Housing Act 2004. That is how a council rating stops being only a regulator's concern and becomes part of the civil fitness standard. The fact that still has to be established is the 'if and only if' limb: the property is unfit only where it is so far defective in one or more of the listed matters that it is not reasonably suitable for occupation.
The landlord agrees to carry out the works listed in the council's schedule to the same timetable and to send photographs on completion; the tenant agrees to withdraw the request for a further inspection if the schedule is met.