Here's a quiz: What do you think when you hear the words Philadelphia School District and green?

A superintendent best remembered for the way she got paid?

Try this one: On Monday, Philadelphia will be named the nation's No. 1 urban school district when it comes to making schools sustainable.

And no, we're not talking about solar-powered metal detectors. Picture buildings whose designs save energy, conserve natural resources, and provide an environment, as Manny Ortiz, a junior at Kensington's Creative and Performing Arts High School, put it, "that makes me for the first time want to show off my school."

The district has won the top award from the U.S. Building Council's Center for Green Schools, whose director, Rachel Gutter, described the city's accomplishment as "amazing."

"I've been to hundreds of schools across the country," she said, "and it was not a difficult choice to put Philadelphia at the top of this list."

The district didn't win the inaugural competition for what Gutter likes to call "eco-bling," investments in solar panels and wind turbines that take a long time to show a return.

"What makes Philadelphia's efforts really smart," she said, "is that they're really focused on things that will immediately make the biggest difference for the environment as well as the students' and teachers' health. So they're looking at things like green cleaning products, increased amounts of daylight."

The district, she said, has been turning heads with new construction as well as renovations of its older buildings.

Last week, the makeover of the Thurgood Marshall Elementary School in Olney won recognition from her organization for meeting the highest standards for Leadership in Energy and Environmental Design.

Among the school's upgrades: no more wet-mop buckets. "Every mop is a microfiber mop," said Michael Pavelsky, the project's sustainability consultant. The lawn mowers and weed trimmers run on rechargeable batteries. Bringing in more fresh air throughout the day, he said, "keeps people from being sleepy."

Another showplace is Ortiz's school in Kensington, which opened two years ago on a weedy, trash- and tire-pocked lot. Compared to his former school, "this is bright, and there's more room," he said. "We're able to move from class to class without getting crushed in the halls."

He and special-ed teacher Joshua Kleiman gave a tour Thursday, pointing out green roofs whose native plants hold rainwater and spare the city's overloaded sewer system. Rain that falls on the gym is stored in two cisterns that provide the water used to flush the toilets.

The insulation is so tight the architects were able to place the performance spaces in the front of the building, across Front Street from the tracks of the El, whose trains pass with a dull roar.

A $1 million grant from the state Department of Environmental Protection went toward a geothermal cooling system that required digging 96 wells as deep as 500 feet. The temperature that far down is moderate, Kleiman said, around 60 degrees, which requires less energy to produce heat and air-conditioning. Over the life of the $44 million building, the green measures are expected to lower utility costs by one third.

Is it a coincidence that students at the neighborhood high school met adequate yearly progress goals in reading and math this year for the first time?

Not according to those who advocate going green.

"Healthy, high-performing buildings help create healthy, high-performing kids," said Janet Milkman, executive director of the Delaware Valley Green Building Council. "And if a fiscally struggling school district with a large population of low-income kids can invest in green practices, anyone can."