2 holes.....both about a meter square, one in the kitchen, the other in the hall.......had to be dug to get to the heating pipes, where there was a leak. This has now been repaired and the holes need filling in/'making good'.
All round excellent - quick replies to my emails, competitive quote, very little wait....and when here, polite, friendly, efficient and professional.
Very happy with the result and would recommend without reservation.