While enjoying the view from a treehouse, Bill Allen, a board member for the Make-A-Wish Foundation from Burlington, Vermont, realized that children in wheelchairs cannot enjoy the same experience. Subsequently, he started Forever Young Treehouses (http://www.ncpad.org/669/2856/2003-03-01) with the assistance of John Connell, founder of the design school called Yestermorrow (http://www.ncpad.org/669/2856/2003-03-01), and arborist Bill deVos. Thus far, the team has built three accessible treehouses.
Click on the following link to view a short video clip (4 minutes) that features Bill, John, and the houses they've created: http://www.ncpad.org/669/2856/2003-03-01