Internal Plumbing

All the water and gas lines were run today. I got a very nasty shock to find they have put the hot water system smack bang in the middle of the wall in the backyard. Every single plan I have received shows it to be located on the side of the house on the Laundry wall. I pulled them up on it and was told that Rheem no longer make a gas boosted solar hot water system that has the gas booster piggy backed to the tank. The amount of wall space needed for the new unit is 2m and the Laundry wall was only 1910. I understand there's nothing that can be done about it but I am very unhappy about it.