Chelsea principle

The larger a mansion is, the larger its ratio of bathrooms to bedrooms. Small houses have two to three bedrooms for each bathroom; large houses can have twice as many bathrooms as bedrooms.

Look at how many bathrooms this place has.
Yeah, that's the Chelsea Principle for ya.

Chelsea Principle

The larger a house is, the larger the bathroom - to - bedroom ratio is.

"Check out all the bathrooms in this mansion!"
"That's the Chelsea Principle for ya."