When Scott Harris and Sarah Jack did a major renovation of their 1925 Teaneck colonial in the summer of 2009, they kept the environment in mind – for example, choosing kitchen counters made of cement and recycled glass. They thought about solar roof panels, but rejected that idea when they were told that they’d have to chop down a towering tree that shades their back yard and house. Instead, they installed a green, or living, roof. The greenery absorbs and filters rainwater, as well as adding insulation, which cuts heating and cooling costs.

For most homeowners, the biggest environmental impact of a roof is simply that it keeps the environment out. But there are innovations that aim to make the roof over your head an important tool in the effort to save energy and reverse global warming. And we’re not just talking about solar panels. There are cool roofs that reflect, instead of absorb, the sun’s rays; roofs made with recycled material; and green or “living” roofs, like the one on the Harris-Jack house.

While the number of energy-saving options is growing fast, these roofs tend to be significantly more expensive than the traditional asphalt shingle roof. As a result, homeowners have been slow to adopt them. But Harris, a graphic designer, and Jack, a publishing executive, made the leap – choosing a green roof partly for energy savings, and partly for aesthetics.

“We wanted to do something to see if we could save on energy bills,” said Harris. “But it’s nice just to look out at it. Now when people come to visit, we have to bring them to the bathroom upstairs to look at the roof.”

Their green installation, on a flat section of roof at the rear of their house, consists of shallow trays holding a light, rocky soil and a mix of sedums, a drought-resistant, low-maintenance plant. The green roof was built using a LiveRoof standard 4″ module. The roofing contractor installed a new EPDM membrane and a protection slip sheet. The project was installed in one day. The project was photographed and featured in the 4/2011 Issue of This Old House Magazine.