CO on a Backyard Pre-Fab? (State of Texas)

[Pierce Fonville]

I would like to add a living space in the backyard of a rental such as a prefab tiny home or a "She House" with basic utilities for a shower, kitchen, and electricity. 

I am looking to do this in the midcities area between Dallas and Fort Worth

Does anyone know what the legalities of this are? Looking for advice on how to solve a problem, not someone to point out that it could be a problem. Thanks in advance!