Sunroom - options or alternatives? (fireplace, furniture, room, interior)

[mrs1885]

We've got land tortoises that are native to Africa, so they don't hibernate. We have to house them in the house if the temps drop below 60. Under normal circumstances it wouldn't be a big deal, but they are quickly approaching 100 pounds and are still very young. They move the furniture when they're bored, can dig and chew through drywall, and are just generally tormenting the dogs and cats.

So I was thinking of putting in a solarium. I learned quickly that they aren't cheap. A simple 15x20 solarium, 3 sided, with a single french door is about $33,000 where I live. I asked him if we could cut it down some. By doing the foundation, a brick knee wall, the interior brick paving, sod, plants, and the double french doors leading from the den to the solarium brought it down to less than half that.

Even that is on the expensive side. So, does anyone have any suggestions for a cheaper way? It needs to be a room that can be heated with the sun and a double sided fireplace that will be blocked off with a brick barrier and wrought iron gates to keep the torts safe. We'll also have birds flying in there, as well as a pond for some slider turtles and fish. It's really going to be more like an indoor garden I guess. Just hoping to find a cheaper way to do it.