Currently we own a unit and reside in it as our PPOR. Recently we purchased a house and intend this to become our PPOR and rent out the unit. We are refinancing the unit and will have a personal debt of approx $75k on this property and an investment mortgage portion of $255k. I have been advised that we can claim the interest incurred on whole mortgage ($330k) as a tax deduction if we reside in the new residence for a period of time, however I do not think this is correct. I would appreciate any input into this matter.