9 reasons to wonder why you don't have a green roof yet

“It’s very important to have sustainability in my life and in my business,” says Deborah Solo, co-owner of Solo Real Estate. As part of that ongoing commitment, she recently installed her second green roof — a roof with a layer of plants growing on a shallow layer of engineered soil media spread over a waterproof membrane — on top of the building at 2016 Walnut Street that also houses the offices of Solo Real Estate (located at 2017 Chancellor Street), apartments and a yoga studio. At more than 200 feet long, it’s one of the largest green roofs in Philadelphia on a mixed-use building. While many buildings in Philadelphia, like the Free Library, the Comcast Center and the PECO building, have green roofs, a private project of this size is unusual in Center City. Solo, after working with Jeanne Weber of Philadelphia Green Roofs LLC to install one here, has plans to install a third one on a warehouse she is working on in Kensington. She's surprised there aren’t more, given all the benefits. 

1. They keep the sewers from overflowing into the rivers. “Every time it rains more than an eighth of an inch here, which is just about every time, the combined stormwater and sanitary sewers can overflow, sending untreated sewage into the Delaware and the Schuylkill rivers. And raw sewage is the worst pollution there is in our waterways,” says Weber. Philadelphia has one of the oldest sewer systems in the country, built in the early 19th century, and stormwater surges are a big problem. Green roofs, by hanging on to a little of that rainwater, can help prevent overflow. (Check out the Philadelphia Water Department's site for more information.)

2. They get rid of pollution. The stormwater issue is the biggest environmental factor, but green roofs have good effects in a more general way, too. The plants filter pollutants out of both the rainwater that passes through them and the air that passes above them. Plus, they supply the city with more oxygen. “Environmental sensitivity is an important factor for us,” says Solo. “We offer our clients that same consciousness in helping them in their home search."

3. They reduce cooling costs. Green roofs don’t help that much with individual heating bills in Philadelphia, says Weber, but it does significantly lower cooling costs. “I had one client who didn’t turn on his air conditioning last year. The temperature of a green roof will probably not rise above about 88 degrees, while a black roof reaches about 159 degrees. And if you have your air-conditioning unit on your roof, that’s pulling in much cooler air and working much more efficiently.”

4. They cool everything down. On a larger scale, green roofs also combat the “urban heat island” effect, in which dark, built surfaces like asphalt streets and black roofs absorb and reflect enough of the sun’s energy that cities can be up to 16 degrees hotter than nearby rural areas.

5. They last longer than standard roofs. “Extending the life of the roof membrane is where the biggest savings come from,” says Weber. They can last more than twice as long as a traditional roof because they’re protected from UV rays and drastic temperature changes.

6. They’re not as hard to take care of as you’d think. Depending on where your green roof sits on the functional-aesthetic spectrum, you barely need to take care of it at all, much less get up there to water every day, as people might imagine.

7. The tax credit. As part of the city’s Green City, Clean Waters initiative, conceived to reduce the stormwater problem, the city offers a tax credit of 25% of the cost of the green roof and waterproofing as an incentive for more businesses to put them in.

8. They’re just nice to live with. Solo and her husband intend to eventually live on the fourth floor of 2016 Walnut, which is currently being renovated. They initially envisioned the green roof both as something to keep the building cool and as part of their own living space. “We pictured an area that we’d walk out onto with a green roof and a deck. But it seemed not to make much sense to stop there.” Solo ended up greening all four sections of the building’s multilevel terraced roof, giving all the renters in 2016 Walnut access to a little green in the city and, she hopes, raising awareness in Philly about green roofs. “Hopefully this will encourage other people to see that it’s doable, it’s manageable and it’s economical,” she says.

9. You can feel good about doing your part for the city. Solo’s deep commitment to sustainability is both personal and professional. “Having been a resident of Philadelphia for more than 30 years, I’ve had the wonderful opportunity to live and raise my family in a green urban lifestyle. It’s my pleasure, then, to help our clients find homes that allow them to experience these benefits, too. At Solo Real Estate, we see it as both good business and good for our community,” she says.