Further Greenhouse/Aquaponics Thoughts

So I was thinking some more. (My husband always says uh oh at this point.) But I was thinking about how to keep the tilapia warm in the winter. From what I've read, they get more susceptible to disease below 70 degrees Fahrenheit and don't survive below 50 degrees. I need to do some more reading but that seems to be my base line.

But since North Carolina gets freezing temps, how do I keep the tilapia above 70 degrees with the least impact on my electric bill or solar supply. So I was thinking (yup, doing it again) and remembered that I'd planned on building a cordwood structure to house the bigger livestock like goats, meat cows and possibly horses. And, of course, to keep things like feed.

So I figured I could also build something similar for the tilapia tank. To house the tilapia tank. Not as the tank. Just to clarify. Then I was thinking (yes, again. It's called brain storming.) that I would also need a warm place for the rabbits and chickens. So I came up with this.

The green part is the greenhouse. Oriented possibly south at the end there to take advantage of the sun going west to east over it. May have to research that some more to make sure that is the best orientation. The smaller rectangle would be the grow beds. The white area would be the cordwood structure. The smaller rectangle in it would be the fish tank. I'll use ibc totes for the fish tank and I plan on getting a second one in a case I need to expand or use it for whatever else reason. Better to have it just in case. Maybe as a koi grow out tank. Besides, tilapia can breed pretty quickly if kept in the right conditions. But I figure having the tank in the structure will keep the tilapia warm in the winter (should be easy to heat the structure if needed) and will keep it cooler in the summer since it will be shaded.

As for the rabbits, I'd once seen pictures of someone's rabbitry where they had the rabbit cages hanging on the outside of a shed. They had a hole for each cage cut into the side of the shed and a nesting box on the inside of the shed. This made so much sense to me. The rabbit could hang out in the cage or go in the nest box for warmth. So if I heated the cordwood structure, it would be a great place to attach the rabbit cages too. 

Now, the brown area would be a chicken yard. The rabbit cages would hang out into this area so that anything hay, food or poo that fell out of the cage, the chickens could scratch through it. Also, the fenced in yard would help to keep predators away from the rabbit cages. But the chickens will also need some place to roost and stay warm. So why not incorporate their area into the design also? I could section off an area in the structure to use as a chicken coop and just leave an opening near ground level for the chickens to get in and out. Probably put a door on the opening to help keep heat in and predators out. I could also make the chickens nest boxes on that inner most wall that separates the coop on the inside of the structure. That way the eggs won't freeze, I can collect the eggs easily and it would be extra protected from predators.

I could check on the fish, chickens and rabbits all in one nice warm room.

So I think this will work out really well like this. What do you think?