So make the classes bigger, perhaps. In a Hansonian vein:

"But while state legislatures for decades have passed laws — and provided millions of dollars — to cap the size of classes, some academic researchers and education leaders say that small reductions in the number of students in a room often have little effect on their performance."
...
Dan Goldhaber, an education professor at the University of Washington, said the obsession with class size stemmed from a desire for “something that people can grasp easily — you walk into a class and you see exactly how many kids are there.”
“Whether or not it translates into an additional advantage doesn’t necessarily matter,” Professor Goldhaber said. “We know that teachers are the most important thing, but teacher quality is not stamped on someone’s forehead.”
http://www.nytimes.com/2009/02/22/education/22class.html

(I don't think I ever met someone who failed to learn something because somewhere in the school there was a leak. Because of no air conditioning, maybe, but puddles or leaks?)