Originally Posted by Osipi
To be honest, I don't really trust old media articles (including the one I just posted) all that much as they tend to exaggerate or get the facts wrong a lot of the time. If there's a number like 57 rooms, it wouldn't necessarily mean they're all for the Cambridges themselves. If there's 9 rooms on the top floor for staff and each room has a bathroom, that's 18 rooms right there.
My best suggestion is to read through the entire thread here on any specific residence to get a well balanced idea.
Actually Lord Snowdon wrote about the rooms. It would make sense for it to have 57 rooms since you would have to take account of the basements the servants rooms ect...