I bought a pre-built tiny house for my yard that brings in passive income. Here's how I set it up.

• Steph Douglass owns 29 rental units and is the co-founder of an Austin real estate brokerage.
• She bought and rents out a tiny house in her yard to pay for her mortgage.
• Douglass says you need less wealth than you think to start investing in real estate. 

This as-told-to essay is based on a conversation with Steph Douglass, owner of 29 rental units and co-founder of Open House Austin. It has been edited for length and clarity.

I bought my first house in 2013 in Austin, Texas when I was just 24-years-old. I didn't think I would ever buy another one, but now I own 29 rental units.

When I bought my first house, I was teaching fourth-grade math and didn't have a very high income — I started at $43,000 and ended my 7-year-career at about $57,000 a year.