Not an exact science, but walk around the area looking for green cabinets. Which one is close to your house. Do they have an extra 1m green cabinet close to them, within about 20m that is new. If so then that has FTTC installed. If no 2nd new green cabinet, then probably no fttc.
I checked some addresses around me on the bt wholesale checker and from that looked to see what my speed was and also mapped the likly router of the cables from the cabinet to my house.