While preparing this issue of Eco-Structure, I had a revelation: While I often reminisce about my school days, I rarely spend time recalling the actual classrooms and buildings where I spent so much of my time growing up.

Reflecting on the brick-and-mortar structures of my education, I began to recall a range of spaces that, seen through my eyes now, were less than ideal. There was the portable classroom where I spent third grade, a stuffy, cramped trailer that was installed next to the main building after a population boom in the neighborhood resulted in too little space for the large student body. In high school, I remember being awed by the interior courtyard where we could eat lunch, but I also remember classes taking place in brick-lined, windowless rooms that felt more like bunkers than inviting learning environments. If you were unlucky enough to have class in the rear of the building during final period, not having a window was potentially a good thing as then you wouldn’t have to smell the diesel exhaust of the school buses idling outside. The crowning jewel of my college campus was a new, multilevel student recreation center, but we spent less time there than we did fighting to stay awake in large, windowless, impersonal lecture halls.

My, how things have changed.

As you’ll see from this issue’s feature stories, today’s learning spaces, from K–12 classrooms and higher-ed facilities to public spaces such as libraries, are often lessons in innovation and interaction.

As the educational realm is, by its nature, fertile ground for architectural experimentation, it should come as no surprise that architects are increasingly exploring the boundaries of sustainable design and construction. The spaces they produce are then used as teaching tools by the educators that occupy them and provide hands-on learning opportunities to students. Among them: the Hawaii Preparatory Academy’s Energy Lab and Tyson Living Learning Center at Washington University in St. Louis.

Both facilities were constructed with locally harvested materials, and their architects paid significant attention to the buildings’ environmental footprints. The Hawaiian lab was designed as a place where students could study renewable energy technologies, so it’s no shock that all of its energy is generated from solar and wind installations on site. The strategy is successful thus far; the building uses only 30 percent of the energy it produces and feeds the rest back into the campus grid. The building’s also quite smart, having been equipped with more than 250 sensors so it can self-regulate its ventilation, heating and cooling, and energy generation.

Similarly, Tyson Living Learning Center was designed with an eye on efficiencya net-zero carbon footprint and net-zero water and energy usethanks to initiatives such as a roof-mounted photovoltaic array, tubular skylights and clerestory windows, and rainwater harvesting and graywater and stormwater management systems that provide 100 percent of the building’s water. Both structures seek to meet the Living Building Challenge from the International Living Building Institute.

Administrators also are improving the environmental performance of existing structures, as seen in the renovation of Shattuck Hall at Portland State University. There, an updated radiant heating system that’s visible to architecture students below was woven into the concrete bones of the original 1915 structure and ductwork.

Architects and designers would do well to pay attention to this subsection of the education market. With new construction budgets already spent or stalled by the recession, renovations and modernizations will be driving school construction for the next three to five years, says Bill Orr, executive director of the San Francisco based Collaborative for High-Performance Schools, who is the subject of this issue’s Perspective column (“Lessons in High Performance”). You should be prepared: It’s one thing, he says, to build in a range of sustainable features on a $50 million to $100 million new construction budget, and quite another to work them into a $3 million to $6 million modernization budget. But even renovation jobs should be cause for excitement: “The improvement potential in these projects is immense,” Orr says. “It creates an interesting design challenge to be able to do meaningful and holistic things when the scope of your project and its budget are restricted.”

Existing facilities also can provide continuing education. This is the core thesis of our regular Flashback column, which revisits older structures to report on the performance of their sustainable efforts. In “Extra Credit," we revisit Sidwell Friends Middle School in Washington, D.C., which opened in September 2006 to much critical acclaim (including an AIA Committee on the Environment Top Ten nod in 2007). Alas, the school’s green roof did not blossom as planned, and had to be replanted this year with a different blend of growing medium and plant species as D.C.’s notoriously hot summers and a rough winter of 2009-2010 proved too much for the original plantings. The school and design team are actively studying the new installation.

My school days may be in the past, but it doesn’t mean I’ve stopped studying new subjects. I relish the fact that, as ’s editor, I’m constantly exploring and learning new things about sustainable design. Here’s hoping this issue teaches you a few new concepts, too.