House hacking a detached garage potential

[German Fernandez]

Hello BP community,

So for some backstory and general knowledge, I am currently house hacking a 3 family in RI and commuting for work in Boston. As I am dreading the drive after 2 years, I decided to purchase a sfh cutting my commute in half and renting out my unit at the multi. 

Option 1- Being a house hacker at heart, the sfh has a unique big detached garage with about 550-650 sqft of space on the second floor that has central a/c and heat, a deck, and electrical box (only thing I would need would be to extend the plumbing from house to garage, about 20 ft maybe (digging trenches in dirt) still needing a bath and kitchenette. If it were up to me I would live in this space and rent house but wife won't allow it. Space would not and could not be considered as a adu/in-law/duplex and cannot subdivide, I would finish the space as a office with bathroom and wetbar and rent it as a room to a friend who also commutes from RI as of now.

Wondering if anyone has any insights on whether I should pursue this. It would still be quite some money to complete as there will be atleast one or two windows that would need to be replaced and other things that could come up along with the plumbing. My issue is whether this would add as much value as the work I could put in compared to option 2.

Option 2 - Not house hacking - The house itself has attic space that I could convert to an additional bedroom adding square footage (right now the house has a 2 bed 2 bath). Then I would also replace old shingles with newer siding, increasing value of the house.

At the end of the day I really like the house its on a quiet street next to a country club (the garage was just a bonus for me at the end of the day) and my goal was to lessen my commute. Is it worth doing option 1 now or down the line, or not at all when I could easily do option 2 and save any potential risk with inspectors, neighbors, unexpected costs. 

Side note: house hacking bedrooms in the house would not be ideal for us. Also, finishing garage would have adequate parking.