Adding on to my 30x40 Wick Pole Barn

[beerplease]

Hello, I currently have a 30x40 Wick pole barn with 3 garage doors and a single man door. She is heated, cooled, and well insulated and overall serves me very well in it's central Ohio location. However I have recently thought it would be great to add an addition to the side(lean too) that is also heated/cooled for a main purpose of dedicated paint room for my auto hobby. So the inside will need to be finished with at a minimum with drywall and possibly plastic walls for the sides of the booth. Now I only realistically plan on painting a whole car or two a year but plenty of small jobs and some powder coating as well. Now I am a pretty handy guy and can tackle most rough construction except concrete but what I don't really have a good handle on is how to accomplish the design of this layout. My thoughts are start the lean too 2" below the main roof for aesthetic reasons and go out about 18' with a poured concrete floor and single garage door with access to the main building via a man door. My questions are these:

1. How to attach the new roof to the existing building, ledger board I presume.
2. What to do with the existing windows on that side of the barn(integrate them into the new space?)
3. What to do with the existing metal siding that will be below the ledger board and new lean too.

I guess I am having a hard time envisioning how to join the two spaces together as one is currently a external wall and has siding and windows on that side. Also outside of contacting Wick Buildings for help I don't have a warm and fuzzy on someone making me a set of plans to build from. Looking for some advice if anyone has tried this on their existing building. I have full plans for the original building if that helps and I have taken pics of the structure inside and out.

Thanks,
Ryan

 

[Youngandfree]

I'd leave it all personally inside the new space. If you want it finished with plastic wall sheets, just attach them to the metal siding.