I'm not quite sure what you are referring to here.
Do you mean the Community Fibre Partnership scheme that is run by BT, or are you referring to one of the government's voucher schemes?
The CFP will cost you and others in your scheme money - and it can be thousands of pounds. You may be able to use government voucher for a part of that. You would be tied to BT for the initial period.
The government's Gigabit Broadband Voucher Scheme allows you (if eligible) to have a connection built by any company operating in your area, with the voucher value (£1500 per home) deducted from the cost. Again, you have to pay any cost over and above the voucher value.
Both may take 12-18 months (or longer) for you to be connected.