Underground is for corpses, they told me,” recalls Claudio Lucchin of the community’s reaction when he proposed submerging a school addition three stories below grade. “They couldn’t imagine having young kids spend an entire day down there.” But the improbable scheme soon began to gain traction. Lucchin is the kind of regional architect who has produced an impressive body of large-scale work in and around his native Bolzano, in northern Italy, but is little known outside its Teutonic province, bordering Austria and Switzerland. Not surprisingly, he’s also the kind of architect who can convince local authorities to do something completely unheard of for the area.

Named for German political theorist Hannah Arendt, the vocational high school trains teenagers for diverse careers in social work. The student population, mostly female, had grown in recent years, with an increased percentage coming from the surrounding Tyrolean countryside. Providing ample classrooms, practice labs, study areas, and a computer lab, the 21,850-square-foot addition—referred to by the architect as an “archaeological dig”—is located behind the existing structures, below what used to be a garden (and beside some unearthed Roman ruins).

While skeptics feared the underground rooms would be dark and claustrophobic, the result is exactly the opposite. Daylight pours through internal glazed walls into every classroom and all the program spaces—even the labs on the bottom floor—thanks to a 44,000-cubic-foot skylit atrium that descends the full depth. Perfectly aligned in plan with the monastery’s cloister above, the courtyard, which also serves as a great hall for the students to gather or hang out in, is oriented to receive south light all day. “The monks knew how to design,” Lucchin adds. According to the architect–who spent two years during design development researching the implications of inhabiting underground space—vertical light from overhead is three times stronger than horizontal light.

“Visitors are surprised by the quality of light,” says Lucchin. “And it is very quiet. There’s a serenity to the space.” The lack of outside noise and distractions makes the underground academy an ideal space for learning. Another added, if not unexpected, bonus of submerging the building is energy efficiency. “Even on the coldest day in winter, we only need to heat the building for one hour in the morning before students arrive,” Lucchin explains. In lieu of air-conditioning, fresh air is cycled through the space year-round. (Because of the lack of windows and greater potential for exposure to radon and similar chemicals underground, air is exchanged three times an hour.) LED lighting on sensors supplements daylighting and mimics the changing color of natural light throughout the day.

Smooth concrete surfaces, bright colors, minimalist furnishings, and bold graphics give the addition, completed in December 2012 following nearly two years of excavation and construction, a contemporary feel that distinguishes it from the rest of the school and could pass for any number of academic or office milieus—with one main exception. Lucchin left the rugged walls of bedrock visible, reminding the building’s occupants of the unique setting.

“This school was a real gamble for me,” admits Lucchin. “There were lots of people against it.” Its success, however—measured by the resounding approval of once doubtful city officials and the students—has allowed the architect to pursue his interest in hypogean structures. Recognizing the scarcity of land, especially in Italy, he is developing plans for an entire underground neighborhood. And while the Hannah Arendt addition is a relatively small project for Lucchin’s 10-person firm—which completed two facilities for the 2006 Winter Olympics in Turin—it is a turning point in the perspective the studio takes, aesthetically, environmentally, and practically, in approaching future work. “The addition is not about form or materials – there’s no facade,” says Lucchin. “It is all substance.”