Japanese house-style sunroom?

So I’m thinking that I don’t want my house to be arctic. While I’d love to replicate the design of an old Japanese house, I also like things like central heating and air, and insulation. So! I propose a compromise: a large sunroom–maybe stretching the length of the back of my house–with tatami floors, dividers, vents, an honest-to-goodness kerosene heater, a kotatsu, a closet full of futon…and the rice paper doors slide open to the Japanese garden, complete with koi pond.

Oh yeah.