Ancillary Rental Income

[Travelle Mason]

Hi BP Fam,

I'm looking to increase the rental income on my triplex, without increasing rent. There's limited storage space in the property, but some potential to have some storage units on the grounds. I'm looking to provide separate space for each unit. 

1.) Would it be better to build storage units or go the Home Depot route and buy some?

2.) If built, what should I make sure it is built out of?

3.) What can I expect to pay for custom built? (I'm sure it depends on sq ft, etc.)

Thanks y'all! Be Blessed!