Hi lokic
Welcome to the community forums
Thank you very much for your interest in joining with us at your new flat.
Have you spoken with our new sales team to see if they're able to offer more support and advise then the postcode checker regarding serviceability? You can contact them directly on 0800 183 1234 and they'll be able to see more at their side.
With regards to flats, you might find that you'd need permission by the freeholder/building owners to apply for a new installation. Can you confirm if you've already spoken with them and have permission and if so, have completed a wayleave permissions for right of access?