A somewhat odd question...

[heretherebefic.livejournal.com]

Hullo! I'm working on a fic, and I've come up against a question that has me stymied. I'm not even sure where to look for an answer.

What would the average size of a guest room be during Bertie's time? I'm trying to have him say something along the lines of "this particular X by X" in reference to a room. Not terribly important, but I don't want to get it completely off the mark.

Any help is appreciated. :)