How to get my crate trained dogs house trained.?

Ok, so here is the situation. I have three mini dachshunds, two boys (rex and rudy) and a girl (ruthie). They are all up to date on shots, no medical problems, and they are all fixed (neutered and spayed). They are perfectly crate trained, and have no problem going to the bathroom outside. When we let them back from being outside they can be with us for ours and have no problems. But once we leave them by themselves is when we have a problem. If me and my girlfriend leave the room they are in most of they time one will pee or poop if we are gone for more than 2 minutes. Again if we are in the room they have no problem and they are fully crate trained and go to the bathroom outside fine. We just want to transition them to think the entire two rooms are there "crate" so they know not to go to the bathroom. Help please on transtioning?