Second Mortgage Loan Rate What Should I Do To Get A Lower Mortgage Rate On My Second Home?

What should I do to get a lower mortgage rate on my second home? - second mortgage loan rate

I come from California. I bought my first house (4 beds) in 1998. I am married and I will soon move out of the house to start my own family. My parents and my brothers and sisters of young people still live in this house. I'm buying into the process of obtaining a second loan on a house with 3 bedrooms, with my wife, but I get a bank mortgage is very high (> 7%) because they think that is the second home is an investment.
What must I do to prove to the bank that this second home not held as investment property? given that this house is relatively lower than the first, and both are in the same zip code. Please inform us if you have experienced the same situation, or if you know how you get a lower rate mortgage. A million thank you!