/diy/ - Do It Yourself

so, as the proceeds from her divorce my mother got this building. it WAS a work-shop where my father kept his tools and did projects for around the house. its a sturdy building, and has survived a half dozen hurricanes without any kinds of problems. it's wired for power, but is not plumbed.

I WOULD LIKE TO CONSULT THE WISDOM OF /diy/ ON THE TOPIC OF WORKING ON THIS BUILDING.

I would like to do the following to it
>insulate it
its open stud on the inside walls, it's always too damn hot (above 90 Fahrenheit). the roof is tin sheeting(no leaks on a 20+ year old building) and I'd like to put some insulating layers on that as well.

>install a ceiling
it is currently an open rafter building, we store the hurricane shutters in the rafters so that access needs to stay, but I'd like to put a ceiling in

>drywall/inner walls
the building has no inner wall face it doesn't need to be good sheetrock if I can get a decent surface

>plumb it
it's very close to the below-ground municipal sewer line
I want to put in a toilet and sink if I can, but will abandon this if I need to

>TL;DR
I want to make this building better does anyone have tips and tricks to do this?

more pictures to follow.