As stated , you contact BT and request broadband service ( without telephony if that’s what you want ) if doing this on line you would have to select the correct address , if ordering by phone , the BT rep would search for the address, as your address seems a little out if the ordinary ( being a barn conversion) this may cause issues if the address doesn’t exist on the OR database or there is no record of it ever being previously ‘served’ , best case scenario, you order , you are given a installation date and told to be available for the installation engineer, who installs the service satisfactorily.
