Garage conversion will increase property value in CA

[Jonard Lopez]

I am doing a cash out refinance and part of the cash, I would like to have my garage converted to a studio unit and rent it out. I am Less than 10 miles from both naval bases and then miles from SDSU. I am getting mixed answers saying that additional living space will increase the value of my house some say it will decrease the value of my house. What are your thoughts? Thanks