I am replacing some crumbling hardboard siding panels on the back of my house (north facing wall) in Austin Texas. I discovered under the kitchen sink window that the water pipes come up out of the concrete VERY close to the outer face of the foundation. The copper pipes are in one of those plastic sleeves to protect them from the concrete and they have black foam insulation on them. There is a part right where they exit the concrete that is uninsulated and the wall cavity had some fiberglass stuffed into it. I am trying to decide what I should do with this situation, if anything. I considered filling the void with expanding foam, but as people in other threads have pointed out, the inner face of the pipes should be left clear to allow heat absorption from the interior.
Our standard practice in freezing weather is to drip faucets and open cabinet doors under sinks. We haven't had any issues, even when it got to 5º during the winter apocalypse in 2021. While I have the wall open, I want to improve this situation - if I need to.