First, pictures:

Interior wall

Ceiling & rafters

Exterior wall

Under the carpet

My 1962-built house in Ohio has this three-season sunroom in back that was converted from a covered rear patio. For the first few years I lived here, I tried to use it as year-round office space, but it stays too humid back there during the spring/summer/fall to not have A/C or a dehumidifier going at all times, and I can’t effectively heat it during the winter, so for the last couple years it has just been used as non-climate-controlled storage. I want to change that this year and make it habitable year-round.

From what I can tell so far, looks like the existing walls are solid enough, so I think maybe I could just add insulation and drywall? I don’t think those ceiling rafters are functional, looks like they’re just hanging there, so was thinking maybe I could remove them and raise the floor off that concrete patio slab some too.

All advice is appreciated - I’m not an expert on any of this, though I do have some experience performing the actual labor that would be required once I know what I need to do.