SustainaBall

Fri., April 24, 8-11 p.m., $75, Free Library, Central Branch, 1901 Vine St., 215-922-7400, sbnphiladelphia.org.

by Katie Karas

When you think of how environmentalists and locavores get down, a ritzy cocktail party probably isn't the first thing that pops into your head. But this Friday, the Sustainable Business Network of Greater Philadelphia — a nonprofit that supports homegrown, triple-bottom-line companies in Philly — will bring together green folk, business leaders and posh drinks at its annual fundraiser.

The event will be held on the Free Library's newly installed green rooftop, which covers 5,000 square feet and contains seven different plant species. Library spokeswoman Kathleen Dougherty says the roof's soil and plants conserve energy by providing insulation, waterproofing and drainage for the building, as well as improving air quality and reducing runoff to sewage drains.

In addition the green setting, an auction will feature environmentally conscious and locally produced goods, including a vintage bike, landscaping services and gift certificates. Cosmic Catering — a company that uses organic foods and composts all its leftovers — will feed guests, and the Philadelphia Brewing Co. will provide booze.

Leanne Krueger-Braneky, executive director of the SBN, says that while she obviously wants people to attend SustainaBall, she wants them to buy locally even more, noting that local businesses recirculate three times as much money into the city's economy than national chains. "If I had one word of advice for Philadelphia consumers, I would say to support local businesses," she says. "[That's] what the Sustainable Business Network is all about — teaching consumers about where they can find local products."

Fri., April 24, 8-11 p.m., $75, Free Library, Central Branch, 1901 Vine St., 215-922-7400, sbnphiladelphia.org.