The 169-Story Treehouse

Andy and Terry live in a 169-story treehouse. (It used to be a 156-story treehouse, but they've added 13 more stories.) It now has a kangaroo-riding range, a WHATEVER-WEATHER-YOU-WANT dome and a hall of funhouse mirrors—the perfect place to hide from the truancy officer who is trying to catch them and make them go to school!
Unfortunately, the hall of funhouse mirrors is also the place where their evil trouble-making twins, Anti-Andy, Terrible Terry and Junkyard Jill live in a doppelgänger mirror, and they take advantage of the confusion to escape and wreak havoc in the treehouse.
Can Andy, Terry, and Jill escape school, save the treehouse from the doppelgänger mirror gang AND get their book written on time?
Read the whole series!
The 13-Story Treehouse
The 26-Story Treehouse
The 39-Story Treehouse
The 52-Story Treehouse
The 65-Story Treehouse
The 78-Story Treehouse
The 91-Story Treehouse
The 104-Story Treehouse
The 117-Story Treehouse
The 130-Story Treehouse
The 143-Story Treehouse
The 156-Story Treehouse
The 169-Story Treehouse
Also by Andy Griffiths
The Treehouse Fun Book
The Treehouse Joke Book
Tales from the Treehouse
Adventures Unlimited: You and Me and the Land of Lost Things