User blog comment:Bobtherandomguy/Children in School: Why would anyone want to see that/@comment-961279-20091219163749

As fast as the boys are in building things, a lot of the materials they use have to be ordered and shipped to their home. I think the school would start taking notice if delivery trucks started showing up on the playground on a daily basis at the same time. Plus, since the Perry/Doofenshmirtz fights almost always cleans up the day's project, that would mean that Doofenshmirtz would have to limit what he does to something that places him around the school every day. Both of these strain how plausible it would be to have a series set in their school.

Sade129 answered PerryPerry's original blog: Dan has said that twice that I know of. To me, this signals that it's not an off-the-cuff remark, but rather a definite answer.

We have 3 confirmed seasons that will cover the current summer. Seasons 4, 5 and 6 could cover the next summer. Seasons 7, 8 and 9 would be for the summer after that. Repeat for each summer with a trio of episode seasons, and there wouldn't be any need to show the school at all.