Off grid-  if you go off grid truly understand seasonality of weather and the sizing of your water cistern.  

They also make it easier to qualify for investors who own many homes or are self-employed.

Sewer is almost always more expensive to replace than inside plumbing, because of pipe size, depth in the ground, etc.

At least your work is going towards benefitting yourself rather than largely benefiting an employer. 

Try Self Employed from QuickBooks. 

If you are ready to make a medium size investment, spend $5,000-20,000 per month on marketing; manage a business operation, and devote full time + to that business, you may have success in building that business to profitability.  

Any specifics about unit size, location, etc?

The properties tend to have larger lot sizes and tend not to appreciate as quickly.

You can get black exterior in a variety of sizes under $300 a window, and the standard white is even more cost effective.

North Austin, near major employers, has strong rental demand.Good luck!