Belated Happy Birthday, Wayne!
I've been busy building a thermal mass greenhouse. Seeing our POA approved a fourth building if it is a 200 sq. ft. or less greenhouse. I had to go with 120 to avoid ridiculous county expenses. 160 sq. ft. of triple wall carbonate, two automatic vents, super insulated, and ~130K lbs. of thermal insulated mass. One module Earthship hybrid style, with rainwater catchment from 136 sq. ft. on the roof. I built in 72 cu. ft. of storage, too.
I suppose you really don't need one in South Carolina!