Seems like you've put a lot of thought into it already. What's preventing you for paying for an engineer survey as a next step to answer the feasibility questions/assumptions you have.
Home Improvement
Home Improvement
I agree with this. Spend a couple bucks to get quotes from engineers and contractors. The “worth it” part will be answered by their quotes, which you set along side comps for houses that are similar to yours with the added space, and what that space allows you to do that you couldn’t do otherwise.
This is definitely something you need to discuss with a local structural engineer. They will know the local code and how much can be supported. Also these types of garages are typically very bare bones in terms of structure so definitely going to be reinforced to support the roof AND addition. Otherwise it's going to cave in. Plus you have to take into consideration adding new electrical, plumbing and HVAC ducts.
To get it done right. $60K for something of this magnitude doesn't seem feasible, but I live in an area with a higher cost of living. So definitely find a good GC in your area and ask them about the deliverables/quotes.
Or if the addition doesn't pan out, make a screen covered patio above it?