In order to rent out your buildings, you will need a Habitat on the plot you wish to have buildings rented out of from.
The Habitat needs to be sustained with clean air in order to continue renting out buildings on that plot. You can only rent out buildings on plots that have a Habitat with clean air.
You can view your current ongoing rentals through the top-level nav button that looks like a House icon.
When renting out a building, you are able to choose the price per hour rate on tasks and the price per unit on resources like water, vibes and power.