I want to have small tea house in my garden,
but I dont know how to build it, specially the roof!
If you scroll down a ways you'll see a thread called "Looking for Construction Plans" which has a similar request as yours.
Here is a link that might be useful: Const. Plans
I belive Dover Publications has several picture/plan books
available....they are reprints from the 1800's or early 1900's. They would be good for research.
It seems like building a small Japanese house would be an almost impossible task for anything but an expert carpenter. A teahouse would be even MORE difficult than that. Why don't you start with something more reasonable, like a gate or nice wooden fence?
This may give you some ideas. The person who built this "winged it", really, and I think it is rather a nice effect, though I'd probably make certain my exterior was done to suit my climate, and I'd probably go for more overhang, as I prefer the look with a wider eave than they chose. But, the idea is sound, and the finished tea house is quite nice.
It would be a challege, but I don't think it would be outside of the realm of doable for someone with decent tools and good, solid basic carpentry skills.
Here is a link that might be useful: Tea House
Those upturned roof corners really stand out as a gaijin effort. If you're going to do such a thing, why not skip the funky Japan-cheezy pool house (see Matrinka's link) and instead try to build a real azumaya or machiai. There's a guy near me who builds the real thing. Check out the teahouse at his website at daikuwoodworking.com
Here is a link that might be useful: Peter Wechsler & Daiku Woodworking
I stumbled on this plan.
Here is a link that might be useful: Tea House Plan
You can buy plans for a small Japanese teahouse from U-BILD Enterprises-$9.95 -"Teahouse Plan 710." Just GOOGLE "teahouse plan," and it will show up.