CHINA, Maine — In March, eight adults and eight high school students from Erskine Academy in the town of China left Maine and traveled to a nondescript city in Guatemala, a place where tourists rarely go. Their mission: to build a house for a needy family—and to do it in less than a week.

Guatemala is a poor country, and for Americans the level of poverty is eye-opening. One of the students, after taking in how little Guatemalans typically have in the way of possessions and money, was clearly struck by the difference between life there and life back in Maine. “I’m just thinking,” he confided to his teacher, “that my horses have a better house than these people do.”

In a matter of days, the students hauled about 1,400 25-pound blocks to the construction site and built a modest cinderblock house with a metal roof for a family of five. Their teacher, Sonia Stevenson, told the people they helped that they didn’t need to go overboard in thanking the students. The students, she said, got more out of the experience than the family could ever imagine.