Okay so we don't really have an outhouse, but the home we are buying is 137 years old and the last owners did a fair job of remuddling it. My biggest turnoof is the bathroom they put in. It is unfinished and ugly but worst of all is the location.

When you enter through the front foyer and go up the main stairs there is a lovely solid wood door with a window in it right smack at the top of the stairs and absolutely the focal point as you climb. Open that door and you find A BATHROOM!!!

They put an elevated plywood floor over the original hardwood obviously to run plumbing. We are removing this and converting it to a small library with some historical books and papers found in the house. The bathroom will need to go elsewhere.

My question is this: While the plaster walls are immaculate, the previous owners for some god-awful reason tore out the first floor ceilings plaster and lathe. Rather than building up to run plumbing, couldn't we run it under the second story floor which is already exposed and suspend it from the wood there? I attached a pic of the area I am referring to. It just seems we could retain the historic architecture that way. Is there any reason why it would be better to do what these previous owners did with the plywood elevation?