My dad's friend did this for years, bought his kids a home and "rented" it to them. He was able to write off a lot of repairs/renovations and improvements, while they wrote off their rent money, which was just the mortgage payment. There were some other little things that could be done, but by and large it was very advantageous for the whole family (better mortgage rate too), and resulted in huge savings for them. Dad called it the "set your kids up for life" plan.

He wanted to do it for me and my sister but funny thing is you still need the money to buy the second house to get started...

There is also something you can (or could?) do in Canadian tax law where you could set up your mortgage a certain way and basically write off the interest you pay. It has a name but I stopped doing that research awhile ago and can't recall. It had some sketchy risks and was definitely "kinda" legal. I am not rich enough to afford a lawyer to make it legal for me....