Plot hole: The whole episode is based on false facts. Cody was getting an A in woodwork and Zack was failing in all his classes the previous year at school (according to their report cards in Ep "Smarter and Smarter"). So Cody knows a lot more about woodwork than Zack and should be able to make a clock, never mind a birdhouse, and Zack should not be able to make a clock.
The Suite Life of Zack and Cody (2005)
1 plot hole in Books & Birdhouses
Starring: Ashley Tisdale, Brenda Song, Cole Sprouse, Dylan Sprouse
Continuity mistake: Right at the start, when Zack is hanging on the tree branch, the long sneaker laces are in front of Cody's shoulder, but when Zack falls, they're gone, though the sneakers have not moved.
More quotes from The Suite Life of Zack and Cody
Trivia: London Tipton was supposed to be somewhat named after Paris Hilton. London and Paris (both cities) and Tipton and Hilton (Hotels).
Question: Where is Estaban from? He doesn't look like he came from America.
Answer: The show never says.
Brad ★