Its always a good idea to talk to the building dept about what you want to do before you start.

The Nest thermostat is a great idea Joe.

It also helped that we have so much volume that I was able to practice on so many houses every day.

I merely want to know about reference materials on this subject and is my idea doable? 

My RE background is slim, so I've now read approximately 783,594 threads here about structuring PM deals, good practice, what to avoid, etc. 

Also this post is in no way meant to advocate any practice or business plan anyone else plans to do.As always I wish the best in your decisions.SIDE NOTE: I notice you are in Canada, my information is even less valid than the disclaimer would suggest

You mention the owner has paid $70k on the mortgage but that isn't a number that matters (since who knows what interest rate he's on or if he's made any extra payments), what matters is what the outstanding balance is on the mortgage and can you offer them a purchase price that is A) Fair to the owner, B) Helps them sell with some amount of equity and C) Gives you room that it financially makes sense.The numbers change based on if you want to flip it or rent it, making the question "does it make sense" different based on the direction you choose.In short, I have no idea how much I would offer...

Buying a college rental could be a great idea, if your going to college that is, that's up for debate elsewhere on the BP forums.

I've pretty much thrown out the idea of the 45k unit.

Gives you a good idea of what folks are paying for similarly-sized rentals in the area.