Sagus and I are developing a plan for a home we want to build one day.

We are looking at an 'outdoor' sort of place as an indoor feature... sort of an arburitum with decks, scattered planting areas, running water features. It would be enclosed with sky-lights so it can be used year around.

How feasible is this?

actually, very.

look into solarium building places, they will have all sorts of ideas.

ive seen a couple of houses around here that have what you are describing, and their tropical plants survive in these rooms through our -40c winters.

Some key words to search under:

Solar Rooms, Sun-Rooms, Solarium, Atrium

With new technologies such as double and triple paned glass, polycarbonate and the like, it is possible to make attached rooms which remain comfortable year round.

I would also suggest checking out Passive Solar Design - Learn about Thermal Mass and how solar gain can be used to heat up a thermal mass.

This is essentially what you are looking for. not only will it provide you with a beautiful space you can use it to reduce energy costs by using it as a solar collector.

Since you plan on having a water feature, you most likely will need a filter of some sort. Trust me on this, you do not need those UV filters, you do not need to run out and spend 1000.00 on filter equipment - I successfully built a biological filter out of material I had laying around the house this summer, an old 33 gallon trash can, foam egg crate and remnants from a solar screen, couple of bricks. The only thing I needed to buy was the pump ($27.00). When we priced koi pond filters we were looking at $799 on up!

I would suggest making it to were your filter tank is exposed to winter direct solar exposure, that way the water will warm up.

There are a lot of companies out there who will sell you a solar room, but they will also sell you on a lot of things that you do not need. I looked into some of these sun rooms and discovered that though they would be perfect for passive solar heating - not many companies are ready to take the plunge and complete the circle and sell them as such.

If you go to your local library you can read up on passive solar design - The same concepts can be applied to the addition of a sun room - I would also read up on the subject of ponds, water falls, and water features. Biological, Organic, Natural are key words for those.

I recently notice that Polycarbonate panels have made it to my local home store shelves. I was very excited to see that, I was not too excited to note the price though.

You should check with the local building codes for this kind of addition. Your local codes will include a list of good materials to use in your local area, give specifications for ventilation and other important key factors. Since no two areas share the same codes, I can not readily say what you can and can not do.

Cheers

David

http://www.wintersundesign.com/snohomish.html

http://www.eere.energy.gov/RE/solar_passive.html

http://www.bagelhole.org/article.php/Housing/334/