I made $20,000 in 5 months by renting out extra apartments in my Sacramento backyard

Kevin Craig/Pilotier Studios

• George Warren added two ADUs to a duplex property he bought in 2004, aiming to earn extra income.
• In December, he started renting them for $2,000 a month each and has already earned $20,000.
• The ADUs have been so successful he plans on building more on another plot of land he owns.

This as-told-to essay is based on a conversation with George Warren, a 67-year-old...