Primary residence or investment property

[Liam Martin Ruane]

So my partner and I are buying our first house which we aim to live in for a small portion before we leave to complete our masters in Spain for 1 year. We would be living in the property for either a bit over a year or only a few months depending on when we decide to begin our program.

My question is, when we are getting a mortgage, should we classify this as a primary residence, or should we classify it as an investment property. I think having it as a primary residence would allow us to only put 3% down where as I don't think this would be available if it was primarily an investment property. What would happen got the loan as a primary residence and then moved out after 4 months?

Any help would be lovely as we are complete beginners. :)