Currently it is a case of
1. Raise money to pay for the network rearrangement to get FTTC to the building via Openreach, perhaps £30,000 to £50,000.
2. Attract Hyperoptic with the Gigabit solution, which means co-operation from the landlord
3. Get the London Mayor to start doing something for areas like this, but as yet no official avenue for improvements is available.
4. Move to a flat with better speeds, simplest solution given London is considered to be fully commercial superfast covered at the simplistic level by Ofcom.