I am up to lvl 8 now and havn't been able to get an appartment. I didn't try any in the back yard area so I could get one accessable out in Omni-E. I kno know if the 4 doors in Omni-E and I have been to all 4 many times. So far can't get in any of them.
There are a lot of house doors in Omni-E, and I have tried many of them. No go.