From my experience I would have to say no. Moving in with my fiancee isn’t going to save me any money. My half of the rent is only $25 less than what I was paying before and utilities will likely be quite a bit higher and erase that savings. I don’t think there will be any savings in any other areas but maybe there are some that haven’t come to mind. My monthly expenses will remain about the same.
The primary reason I won’t save any money is that our two bedroom apartment is about twice the cost of my studio apartment. The new apartment is a lot nicer but I’m not sure if it is really worth the extra money. I suppose this could be considered lifestyle inflation and I would guess lifestyle inflation is a major reason why many couples don’t realize much or any savings from combining their expenses. In our case we didn’t have a lot of time to find a new place so we couldn’t review all the lower cost options. Next time we will be able to get a better deal. I am not complaining, there are a lot of benefits from our combining our households but saving money isn’t one of them.