It depends. I had all my woods and wedges fitted there. It's normally done on mats where the track man can monitor all the necessary data but when I had my wedges fitted I started off inside and then went outside onto the grass. Here they tested the different sole grinds and how the clubs reacted with the turf. I can't see why after they have found you the necessary club that's suits you the best they can't go out onto the grass to see how it reacts. I just normally phoned them up and they fitted me in. It does cost to have the fitting but if you buy it from them then this is reimbursed from your purchase.  Hope this helps!