Hi Mary,
we're building a 20sqm big round-house (for our lucky chickens), but I don't know if you would like to build it with the post and beams structure or in Nebraska-style. In GB you can buy a very nice book called " The low impact round house" by Tony Wrench. It's about 9-10pounds. You can fill then with straw-bales instead of other materials he uses for his round house.I hope this helped you. Maren