They deploy the OLT in the local Openreach facility and then build out from there. Beware however, they do not dig any of their own trenches etc - they rely 100% on the OR ducts that are already in place and will deploy their fibre in those. They also deploy to poles. Overall - it all needs to be OR Green PIA...
So, as long as you have ducts all the way to your front door - or are pole fed - you SHOULD end up getting service from them...
Good luck.