There are strict laws in Texas that govern what a landlord can & cannot do concerning a rental property. 

Landlords are supposed to "bring the property up to Code" when it becomes a rental.

Smoke alarm locations, rekeying locks, special deadbolt locks, peephole locations, eviction process, security deposit handling, and repair timelines are just a few things that are covered in the law. 

Why should a landlord be concerned? A landlord could face a lot of liability & lose it all in a lawsuit if they do not conform to the code.