This is an ethernet leased line service,1 Gbps access on a 1 Gbps 'bearer' which is not a straightforward or direct comparable to a broadband service which is shared/contended. There are also stricter service levels and response/fix times being a business service. Unfortunately this makes it quite a bit more expensive than say FTTP. However where this circuit is located there is no possibility of any sort of FTTP, FTTPoD or even FTTC, nor any other Alt Net providers (currently though that may change)
There are many companies out there that will provide (re-sell) leased line circuits which in turn are typically bought through one of the large wholesalers. The final 'tail' or connection between the premises though is typically provided by one of the large established telco's which may already have the fibre in the ground and the connectivity at a local Point of Presence (like a BT exchange) - i.e. the likes of Virgin Media Business or Openreach.
Of course you can order such a service directly from BT, but you are better off shopping around as the actual rental prices, excess construction costs etc vary quite massively between providers and also depending on where you are in the country. There is no one size or standard price.
If you are contemplating this seriously, PM me and I can put you in touch with different providers that quoted at the time.