Assuming girl friend is not on title, or has a written lease, and comps say you can do a quick flip.Verify loan balance, with a pay off request from lender.You could buy sub2, since you're doing short term, then give girl friend 30 day notice to vacate, start eviction as a back up.Then clean it up and flip.1031 does Not apply here, it's for long term investments, not flips.

Keep studying and keep networking and growing and apply what you know.

These blogs is written for the state of California if you don’t at least have a basic understanding of the real estate principals and real estate financing applicable to your state, I suggest you go to your public library, book store, amazon.com, whatever and get a copy of the real estate principals, financing and laws that apply to your state.

I would not be a business, so i am not sure those regulations apply to me?  

I think that theme applies here.

I also did not say it must be stored, just that your local laws would apply.

If the resale market is not quite right, you can convert the property to a rental for up to three years prior to sale, and still apply the capital gain exclusion on the sale of a primary residence to your sale profit.

Applied Accurate Knowledge is Power"You can learn knowledge but do nothing with it and get nowhere.

You should be able to determine the adjustment to be applied for properties close to commercial or on certain busy streets.Who can best analyze comps?

Don't know if either applies to your property, but if it does this could be the reason.