http://www.kalwall.com/about.htm

I can only suspect the cost would be prohibitive, but this stuff is
pretty impressive. An aerogel core with some sort of acrylic casing, it
allows a whole lot of light through, and somewhere it says that a 4 x
35' panel (that is feet!!) weighs only 210 pounds and has an R value of
about 20... Like building with styrofoam board that you can see
through, it seems. Can't find a price though...

They built a lot of Milwaukee's new baseball stadium out of it:
http://www.kalwall.com/15.htm

Somebody build a greenhouse out of this stuff and tell me how it works.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit