I designed a 2 bed 1 bath stacked triplex that fits on a 30' wide lot with 3' side yards and we can build it for $174 a sq ft hard cost. we do them where the land is 10% of after repaired asset value which in our market is 50k approx. we study multifamily trends and stay with it.

@Mohit Arora recommend you spend more time studying TX landlord-tenant statutes.Your lease is probably pretty basic as it didn't really cover this issue - and it probably doesn't really cover a whole lot more.Google & download as many TX leases you can find to copy & paste to improve yours.

Studying commercial property investment could greatly accelerate the time line.  

Renting to students in majors that are study intensive (STEM) can cut down on the damage and engineers like to fix things.

I have no deal experience and all of my knowledge comes from self-study and networking.

I’m researching my finance options and studying the market.  

Does Cube Smart do the feasibility study for you as well?

@Sandeep DhallI use DIY and I love them for the algorithm-based studies.

Study financial history when speculators bet long with short term money.

Whether you pay off the properties or keep them, don't forget that you can do a cost segregation study and use bonus deprecation to off set taxes.