When David Stiles and his wife, Jeanie, wrote "Tree Houses You Can Actually Build," they ran a small newspaper ad to find treehouses near their Long Island home.
"Just in the small town of East Hampton we were contacted by about 20 or 30, and those are just the ones we found," says Mr. Stiles, a designer, builder, and illustrator. "There must be 50 in East Hampton at least, and millions across the country."
History is replete with treehouses. European monasteries sprouted treehouses in the Middle Ages. In ancient Rome, Pliny the Elder records a banquet for 18 people in a tree.
In America, treehouses were big in the 18th century. And now, a treehouse revival appears to be growing by leaps and boughs.
The two-year-old World Treehouse Association, which has 250 members, held its second annual meeting Oct. 10-12 at the Out 'n' About Treehouse Resort in Takilma, Wash. Some 25 people paid $170 to meet experienced builders and practice new treehouse construction techniques.
As an "InTreePreneur" with his own treehouse design company, Peter Nelson has built 15 "full-scale" arboreal dwellings. Adult treehouses cost from $5,000 to $45,000 and are sized from 100 to 450 square feet.
Mrs. Stiles says treehouses for kids are on the rise among people who want more contact with their families and the outdoors - as well as a little distance from modern technology. The couple encourages families to build together, or even for youngsters to tackle the job.