Whichever are combined into a single device.

I'm thinking of downsizing it and combining two of the units to where it might at least a 2/2 but maybe a 3/2.

You may be able to Group like kind properties in some cases (combining hours)

Too many people trying to get by on some combination of fake jobs, government subsidies and charity. 99% of all the problems these people face, including the homeless, would go away if they got off their duff and started working a real job.

rent is a function of the rental market, and a mortgage is a function of price and rate. 

@Brandon Ja - The standard answer here is to check with your CPA, but from my standpoint expenses that add longevity and functionality to an existing property (including adding square footage) would make that a capital expenditure that can be depreciated over time.

A great high functioning portfolio along with a decent W2 goes a very long way to achieving your goals. 

*Tenant occupied properties that need a lot of work - especially when combined with my point above.

WikipediaSustained and significant population growth: Prices and rents are a function of supply and demand.

combining multiple sales and 1031s and buying one larger asset.