Do garages count towards projected rental income

I bought a SFH a few months back and have been working like crazy to improve the place. I'm thinking that when I finish the improvements I could sell it and make a few bucks. What I really wanted all along was to buy a duplex or triplex but I didn't see any I liked in my budget so I bought the SFH. What I'm thinking is that with the profits from the SFH I could either buy a nicer multi or buy a cheaper one and use some of the profits for improvements. In recent zillow searches I saw some multi's in my area that had multiple garages. I understand that you can use projected rental income from other units towards what you can be approved for but I've never heard anything about garages. On one particular property it would make a huge difference. I'm quite certain they would be very easy to rent out but not sure if lenders see it that way. Any thoughts, advice or shared experiences would be greatly appreciated. Thanks