The Treehouse Book by Judy Nelson, Peter Nelson (2000, Paperback, Illustrated)

Master treehouse builders Peter and Judy Nelson, with David Larkin, have embarked on yet another treehouse-discovery expedition across America, this time adding the investigation of backyard playhouses to their agenda. Now, in The Treehouse Book, they reveal their findings, illustrated and described in the most complete volume yet. From casual treeshacks made from discarded lumber to multitiered feats of fancy, they found shelters representing
myriad builders-interesting characters ranging from childhood fanatics grown up, to weekend carpenters, to those who want their grandkids to have the best clubhouse on the block.

Detailed how-to information, including plans and drawings, is woven with behind-the-scenes tales of each structure's occupants and stunning interior and exterior photographic explorations.