Where did this expression come from?

I’ve heard people say “So and so is in the house”. I’ve even seen it in ads. Where does this originate and what does it mean?

This is purely speculative, but I would guess it came from either House or Hip Hop music…

When House music was first becoming popular in the mid 80’s (I’m talking from a UK perspective) it was very common for songs of house music to use the word house in the title and/or lyrics.

As for hip hop, it seems to me that using a term like that is quite common… it wouldn’t surprise me if it started as saying from urban areas…

WAG: It came (originally) from Elvis concerts… ?

When Elvis finished singing, they would announce “Elvis has left the building!” So that his fans would put their panties back on and go home.

I hit submit instead of preview…

And then rap artists sort of turned it around in the '80s…