Treehouse design is climbing to new heights. Innovative designers and builders around the globe are raising the bar -- and the roofs -- on these lofty structures. Among this creative clan is Seattle-based Treehouse Workshop, which has built some of the world's most inspiring
The firm's principal, Peter Nelson, has been advocating arboreal design for more than a decade with popular
cof- fee-table books like his latest "New Treehouses of the World," published in 2009 and pictured at right.
The stunning design pictured below is one of the firm's more recent projects.