Plumbing

I am a contractor in Sacramento and somehow have never worked on a Streng Bros. home. I am trying to find out where the original plumbing typically was run so that I don't have to take the house apart to figure it out. Also, what material were the pipes made of? Galvanized pipes? Copper? My client wants to run a tankless water heater and I am trying to do the research based on the experience of others. Whatever info you can provide will be helpful.

Thank You,
Gene Kelly