Relocated Building Rehab - Project Workshop

So almost a year ago, Mrs. Ironsides and myself purchased our first home. 

One of the big selling points for myself was the amount of garage space, relative to the amount of vehicles I own. (Oversize 2 car attached and a single car detached) 

The house is a traditional New England style cape, that once had a single car attached garage.

The prior owner who did the bulk of the renovations was apparently a car nut, who decided to not only rebuild the attached garage bigger and taller than before. But to also relocate the old single car garage to a newly poured slab in the backyard!

Enter, project workshop: 

(someone buy this datsun lemons car plz)

As you may have noticed, the garage was previously attached to the house and the area where it intersected the roofline is still very much open to the elements (some plywood and covering has been added, keeps snow out but not water)

My goal for this space is cold winter storage for one of the project cars (giving Mrs. Ironsides her winter garage spot back) 

As well as a flexible storage and workshop space. The overall size is approx 16ft x 24ft. 

What I'd like to do is move the door to face the house, add 4 swing out windows to allow more natural light in and finish out the exterior in vinyl to match the house. 

Now, I have minimal carpentry or construction experience, but am armed with an industrial design degree and above average google/youtube skills so I feel confident in tackling the job myself. 

The state of the roof/wall interior:

If i have my head wrapped around this correctly, it seems like once I strip the siding and the roof off,

I will need to build a temp wall to support the roof and reframe the cut up wall, and sister the roof joists down to allow me to box in a soffit, basically mirroring the opposing side of the structure. 

I can frame in my new windows in the process and then work around and move the door to the opposite sit. 

The other bit I'm not familiar with is how the structure currently sits on the slab. Whoever moved this structure decided to pour a nice even slab, and lined the perimeter with mortared in cinder blocks. The cinder block voids are not filled in, and the structure sits right on top. I've looked this over fairly thoroughly and it does not appear that the structure is anchored to this at all. Not sure how much of a problem that is, or how to go about anchoring this if need be. 

My other homework is to determine how or if to acquire a building permit. We juts put up a fence around the backyard, but the structure is not completely obscured from view of the street.

The town parks/grounds department is located at the end of my street, and town employees drive past our property all day, so I expect its worth pulling the permit, I will give the building department a call this week to understand the process. 

Like I said my experience with carpentry is fairly limited but I feel like this project is within my wheel house and I would really like to avoid paying someone else. Welcoming any thoughts/recommendations/suggestions.

Cheers! -Nick

Need photo of the 2-car space. 
 

If the detached garage is not anchored to the foundation.. it's definitely a problem.. you will need add some anchor bolts at a minimum. Are you sure the block at the base isn't grouted solid - at least some of the cells? 

I don't think you would need a permit because you're just doing repairs.  

You should be able to tap the sides of every block and hear a difference if any are filled. I'm no carpenter , but would anchoring the structure to the blocks, and filling around the anchors, be enough to satisfy code? Aren't the anchors normally long and poured into the slab? SVRex to the courtesy phone !

I too had thought that I do not need a permit for repairs to an existing structure, but a quick look over the town website noted repairs as a permitable action, i'm sure when i call the building department they should be able to clarify.

As far as I can tell, the blocks are all hollow, you can almost see into some of them. My first thought was to use a hole saw to open up the wooden frame to the block cavity, drill down into the slab and install a very long lag bolt that protrudes above the wall frame(12" or so) fill the cavity with concrete and then use a large washer or peice of flat stock and nut and bolt the top. Outside of that I think lagging the structure to the block isn't much better than current as the blocks are not truly part of the slab. 

Pics of the attached 2 car: 

Fun fact learned from the neighbors, there is a 20x30ft room behind the garage, this is now a finished bonus room, with no access to the house. I learned that the guy who did the renovation had originally had this room opened up in to the garage (there is no foundation partition separating the spaces) and this was a "showroom" for his restored mustang collection. 

He unfortunately passed before finishing the project and the flipper that came in to finish the property built the space out as a family room to entice normal buyers. I brought the idea of knocking the wall down for super garage to Mrs. Ironsides, but she was less excited about it that I was...

Two project cars on jack stands all winter should cure her of that notion.  The angle being that if you have the extra garage space, she still gets a garage space for the daily driver ;)

In reply to Ironsides :

Around here that bonus room wouldn't be legal unless it's floor is XX inches above the garage floor. That's for carbon monoxide accumulation issues. I can't remember how much XX is, but it's less than a foot.

You might be surprised at how helpful the permit office is.

We always pull one because they're really knowledgeable and can answer stuff like what part of the state building code to look for reference. I think that lots of the answers you're looking for will vary state by state.