that is an awesome idea, maybe when my kids are older I can do something like that, but right now I don't think my 5yr old would leave it alone! He is always looking in on the fish and wanting to feed them, and I really shouldn't do something that big until the economy levels out and power bill goes down, although solar power would be a good choice...hmmm...
if u just dubble glazed a conservaoty or something to retain the heat at night i think you could possible do it without a heater (at least during the summer)
you should go tropical all over tho.. so its like a whole room full of tropical plants / animals you could get some lizzerds a snake or 2 as well? maybe afew birds lol go the full works plants and all =]
I'm still young but I have dreams of building an indoor pond for my turtle (and perhaps plural turtles by then!!). I've got it all figured out, great idea.
This is #71###ing quality. But as others have said heating bills and not being able to view the fish from the side like you do in a glass tank would put me off. Respect for giving it a go though! If I did this I'd have to live in a Hot country. Fish choice? Wild discus without a doubt, they would love it in there and breed easily I bet. Get a huge 1000 gallon+ monster and breed Heckels or something.
Professional fish breederes do this in asia with huge ponds with amazing Arowana.
edit: Thinking about it there is a maidenhead aquatics at Wembley that has has a huge indoor raised pond with the biggest Koi carp I've ever seen...It also has a decent sized viewing window on one side...perfect!