There are special rules about housing parish clergy as a house is generally provided by either the Diocese or the PCC and is not a taxable benefit as it is considered by HMRC to be customarily provided for these roles and to be necessary for the better performance of the job.
However if a PCC provides housing as part of an employment package for other posts (e.g. youth worker, caretaker etc.) either “free” as part of the package or rented to the person for a rent less than the market rent, then it is likely a tax liability will arise as this is considered by HMRC to be a benefit in kind and the employee will have to pay tax on the value of the benefit.
There is detailed information here and there are certain exemptions.
If there is any doubt about whether an exemption applies it is essential to seek guidance from HMRC.