Well the aim is hopefully to have insulated it that well that once i get it to the right ambient temp I require it won't be too expensive to run. It's never going to be cheep to run, but neither is my existing tort room. Also the ultimate goal would be never have to buy food again. Not saying its possible, but I'm going to give it a shot. This should offset some running costs. Fruit is not a problem from may to November. Plenty of wild fruit trees around here. I also have an apple,plum and cherry tree in the garden. Need to get a fig tree, although I know where there is one on a river bank in the middle of nowhere.I'm growing quite a few things indoors experimentally for the first time. I think that a room like you're creating is breaking new ground Many of us will be watching you to see how it all works.
I tried growing a small young grape vine last year. It was doing well under my fluorescent grow light, but then one of my cats got to the plant (mine eat anything green) and it never recovered. I plan to try it again soon. I'm growing hibiscus inside for the first time and have wondered that too.
@Yellow Turtle01 & @Odin's Gma does your hibiscus flower indoors?