I would agree with sdr to talk to some home loan people. However my advice would be that you worst case it. That is, presume that the lender will treat your purchase as an investment property purchase no matter how much you tell them it is not going to be that way. If this is the case you will not get the same rate as an owner occupied rate. You can even go so far as to literally put your home on the market for sale and many lenders still will not take the bait.

With regards to your ratios that the lender will use for your approval process, it doesn’t really matter how much equity you have in the home, they will more then likely count both mortgage payments, insurance and property taxes in the calculation because you do not have a tenant in place. Again, this is my speculative answer and it is a worst case answer. As sdr said talk to some lenders or mortgage brokers and see what they say.

If you had some time, then moving out, renting a place and getting some tenants in your home with s a little bit of seasoning would help mitigate the situation.