The first generation of net-zero communities, which were designed to add no carbon to the atmosphere, are entering their second decade. Beddington Zero Energy Development (BedZED) in London is about 15 years old now; and the first phase of Dockside Green in Victoria, Canada, is now 10 years old. In a session at the 2017 Greenbuild in Boston, Steven Dulmage with Urban Equation and Justin Downey at RNWL outlined lessons learned from these early sustainable communities and how they informed second-generation developments, such as Zibi in Ottawa, Canada, and Hazelwood Green in Pittsburgh, Pennsylvania.
According to Dulmage, BedZED, which has 82 homes, “didn’t hit net-zero carbon projections.” While the project successfully reduced emissions from transportation — as more residents walk, bike, or take mass transit — the biomass plant built onsite didn’t work out. It ran for a few years and then was discontinued. “It wasn’t economic to run, so they converted to gas. The business case for the biomass plant wasn’t well-thought through.”
Dockside Green in British Columbia, which has 26 buildings that house 2,500 people, was “built up at the front end during the recession, which was very painful for the developers,” explained Downey. While the developers used a phased approach to development, Downey seemed to say the roll-out of those phases was too aggressive. “They didn’t wait for absorption,” meaning they didn’t build to the pace of tenants buying apartments.
Also mentioned: One Brighton in the UK, built in 2009, was the first major development built using the One Planet Living framework. While the development reduced carbon emissions by 70 percent in comparison with the average neighborhood development, that’s not 100 percent. Still, homes there sell for a 10 percent premium over comparable real estate because of their inherent sustainability and resale value. There are also other benefits: residents who move there sell their cars as they can walk and bike everywhere. No cars means much less spent on transportation and fewer carbon emissions.
The latest generation of net-zero communities have learned from these first models and may have greater success reaching environmental goals.
Hazelwood Green in Pittsburgh, which is now under development and will transform 178-acres of old industrial property along the Mononogahela River, could achieve net-zero by using onsite renewable energy for 40 percent of energy needs and a “geothermal field” connected to the river for the rest, explained Downey. “It’s a smart design concept — the ambient geothermal loop and renewable technologies can get us to 100 percent.”
The Zibi in Ottawa, another community now in development, is using very ambitious sustainability goals to “find synergies among stakeholders,” Dulmage said. While developers are often conservative and “reluctant to invest in sustainability strategies, ” at Zibi, “sustainability is instead used as an alignment tool to reduce risk.” The developers are pursuing a thermal distribution pipeline using waste heat from a nearby Ottawa Hydro facility, with a 50/50 split on the cost and savings for the system between the district energy company at Zibi and the utility. The developers are also using “values-based procurement.”
As for the future of net-zero communities, Downey sees developers now dictating hard energy performance requirements. For example, in a recent RFP for a new building, Hunter College put in a 100 kwh per square meter performance target.
The conclusion seemed to be getting net-zero, or, really, near net-zero communities, right is still a challenge, but a worthy one given “we can only add 600 more gigatons to the atmosphere before the planet hits dangerous levels of warming. We are going to max out emissions by 2025.”
Sadly, the public may or may not care about these numbers. But if these developments are sold from a human health and happiness perspective, they may be more likely to succeed. The average BedZED resident knows 19 of their neighbors, which is four times the UK average, said Dulmage. On that front alone, this early sustainable development sets a model all its successors should follow.