Primary Residence vs. Investment- Refinance

[Ameer Eddin]

I'm hoping I can get some feedback on what constitutes a primary residence for underwriters on a conventional loan. I have a friend that asked for advice on refinancing her first home which was purchased 2 years ago with a primary 30 yr fixed conventional loan w/ 10% down at 4.125% (PMI included). She recently got married and purchased a second home within the same city which is only 25mi away from the first home. She would like to refinance the first home on a 15yr conventional fixed as a primary residence since she will be getting a better rate, but she filed her taxed using the new home. She's currently paying the mortgage and utilities on both properties with no tenants or rental income. Any advice or suggestions I can pass along would be great.