Re: Freeview with no aerial?..
The restriction on a listed building regarding aerials, would be to do with external ones.
According to the information you supplied indicates you require a 'Group E' aerial mounted in a 'Horizontal' plane pointed in the direction of the Transmitter Site (Black Hill).
I suggest you get an aerial of suitable size (fits comfortably in the roof space, e.g. 18 element) and add a Pre-Amplifier (470-890MHz) to make up for the signal loss caused by the roof.
I use a Group C/D and Pre-Amp for my situation. It is a standard one (not erroneously called a 'Digital aerial') When I checked my Post Code for suitability, I was informed "Not Available For Your Area". Pile of poo!! I've had Freeview for 7 years!!
Good luck with your purchase, please let us know how you get on.
Kind regards James