I’m an Architect and that was one line which we used during my undergraduate days to describe a mansion, it was common among my colleagues and lecturers, it came to my head again.
It’s just like asking me a certain definition and because I defined with what I’m used to you then said I plagiarised.
I think if you search through further you’ll realise it’s common among people involved in buildings

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I’ll send more common description that looks exactly like this! I think it’s common among people in the built-environment to describe fancy buildings.