Great news - the utility (gas, electric, water etc) searches are back! Cardiff council kindly did this for us - which involves contacting the utility companies with the site location, and they informed the council if the utility is run on the site. I picked the paperwork up last week. Thanks to Will for organising, and putting up with my pestering!
Oh, and I'm giving a talk and slide show about the show garden in work tomorrow! Slightly nervous. I have one hour with no notes so will have to wing it.