Repairing drywall behind washer
So I had a plumber over the house to investigate why my washer was not draining correctly. It turns out that the 50 year old pipe behind the washe had completely rusted. It was un-snakeable so the plumber gave me the option of breaking through the drywall and replacing the pipe. He mentioned that he would not fix the wall. With no toehr choice, and the fact that the guy charged my under $100, I said go for it.
So now I am left with a sizeable portion of the wall missing behind the washer, which isn't a big deal looks-wise and the washer covers it. But I am concerned with energy loss so I think I should fix it.
The problem is that there are a few pipes that come out of the wall there. Questions: Is this a job strictly for a professional (even though looks isn't a big issue)? Am I right to be concerned about enery loss here?