I'm in the yeshiva in Staten Island for yomtov, and my nephew, Harav Gilan Grant, has a very nice sukkah for the children next to his. Passing by a yard sale, he saw this "Step2 Storybook Cottage Playhouse," and replaced the roof with a schach mat. It's 100% kosher- ten tefachim, seven by seven- though it might be more comfortable for people who are under three feet tall. It even has a washing station, so you can avoid the issue created by leaving the sukkah after kiddush to wash.