I live in north TX near Fort Worth. Not a humid place but a very hot place, averaging 104 degrees in the summer outside in afternoon.
I was planning to buy a Tuff Shed 16 X 20 shed with asphalt roof and a standard home door and a single small window. I contacted Tuff Shed and discussed my interest in making this a climate controlled building with air conditioning/heating unit and insulation.
They said that insulating it would be something I would have to set up on my own.
But, I don't know how that is possible as they pre-fabricate walls with OSB siding. Essentially 2 x 4 framing and OSB. I have a TS now and they are very solid and well built. Been in place for 11 years without issue.
I would think the shed would require a climate barrier layer wholesale on the shed prior to siding. In other words a plywood layer with vapor barrier and then siding. Does that make sense?
This implies that Tuff Shed may not be the best route to go but rather a custom built shed if climate control is desired.