The Partihaus household is a pre-made household that resides in Windenburg from The Sims 4: Get Together. The household consists of Marcus Flex, Paolo Rocca, Jade Rosa and Eva Capricciosa, who are also members of the similarly-named club.
The household bio states that Marcus invited Paolo, Jade and Eva to stay at his house in Windenburg. Since then, the party has never stopped. But because only two of them have a job, they don't have a great income and have troubles with paying their bills.
The name of the household is derived from "Party House", with "haus" meaning house in German.