Only if your community property state has a specific law.
This is NOT true otherwise.
Prenups CAN and DO get drafted which envision living in the same house.
They even have provisions which say that if the house is sold, the PROCEEDS are still subject to the prenup.
living in the house is not really relevant if properly drafted.
I suppose.... Really, if the power of prenups fade and get mixed in with joint property with time, that's the way it should be, as over time, the wealth in the marriage ~should~ be expected to be jointly earned.