It's a fair question. I originally assumed that the White House might have much older plumbing, but it was completely gutted and renovated about 10 years before

It's a fair question. I originally assumed that the White House might have much older plumbing, but it was completely gutted and renovated about 10 years before LBJ took office, and I have to imagine the plumbing was designed to commercial standards, if not better.[1] The description of LBJ in the article makes him sound like a narcissist, or at least a manipulative person, and a common technique is for the manipulative person to claim that they've personally witnessed (or in this case, own) something superior to what they've asked someone else to create. He probably really did have a very fancy shower head arrangement in his home, but I doubt very much that it had the kind of pressure and temperature he insisted on for the White House. He probably just wanted something even more extreme, and his approach worked. [1] https://en.wikipedia.org/wiki/White_House_Reconstruction https://en.wikipedia.org/wiki/White_House_Reconstruction