Can a city be sustainable? That’s what our 2016 edition of State of the World investigates. In his chapter, “Reducing the Environmental Footprint of Buildings,” author and project co-director Michael Renner explains what actions cities can take to make their buildings greener.
Buildings are some of the biggest users of materials and water, consume nearly half of the world’s energy, and contribute almost half of global greenhouse gas emissions. With more buildings sprouting up every year and existing ones often being inefficient, cities have begun to tap into their toolkit of policies to help reach sustainability goals.
According to Navigant Research, the total floor area of the world’s buildings (commercial, residential, and industrial) is predicted to grow by 13 percent between 2014 and 2024. Already, the world has 152 billion square meters of buildings, roughly equal to the surface area of the U.S. state of Florida or most of the country of Tunisia. This floor area is expected to expand to 172 billion square meters by 2024.
Buildings are some of the biggest users of materials and water, consume nearly half of the world’s energy, and contribute almost half of global greenhouse gas emissions.
Many industrialized counties, especially in Europe, are concerned about making their existing buildings more efficient. More than one in three European homes is more than 50 years old. Cities in Europe, North America, and elsewhere are looking to reduce their environmental footprints by encouraging (and in some cases requiring) retrofits of existing materials and systems.
With the growth of new buildings and the aging of old ones, what can cities do to steer building developers, owners, and users in a greener direction?
Four Methods That Work
Tapping into their policy toolkits, municipalities around the world are using a blend of building codes and permits, zoning regulations, building performance ordinances, and other mandates and regulations. Taxes and other financial policies can provide additional incentives. Subsidies can reduce the upfront cost of retrofits and ensure that lower-income residents are not left behind.
Here are four tactics that cities and their residents are using to push toward urban sustainability:
- Building Certifications
Hundreds of green certifications exist today, ranging from standards for equipment and appliances (such as Energy Star and WaterSense) to certifications for entire buildings (such as BREEAM and LEED). These rating systems vary in ambition and are often adapted to local factors. In the water-scarce Middle East, for example, the United Arab Emirates’ Estidama system weights water efficiency very heavily compared to other major certifications. The Living Building Challenge available in the United States and Canada is more ambitious than most rating systems: to gain certification, a building must generate all of its own electricity and use only water collected on site.
Although most building sustainability certifications are voluntary, some cities require minimum green building standards. Portland, Oregon, and Vancouver, Canada, have mandated that all new public buildings meet the LEED Gold standard.
Building Certification in Action:
The headquarters of the Bullitt Foundation, a group that funds environmental organizations in the western United States and Canada, exceeds municipal green building requirements adopted in Seattle, Washington, and has earned the more ambitious Living Building certification. To reach this standard, the building collects rainwater, produces all of its own electricity, and uses materials that do not contain hazardous materials. The Bullitt Center promotes the health of its occupants with active designs (such as “irresistible” stairs and compelling views), provides equity (all work stations are within 30 feet of a window), highlights aesthetics, and is built in a location that supports pedestrian-, bicycle-, and transit-friendly lifestyles.
The Living Building-certified Bullitt Center touts itself as “the greenest commercial building in the world.” Photo: Bullitt Center
Active design in the Bullitt Center encourages healthy activity. Photo: Taomeister
- Building Codes
Building certifications are sometimes time-consuming and costly. But cities can set their own standards by creating new building codes and revisiting outdated ones. Like certifications, codes can be voluntary or mandatory. Copenhagen, Denmark, requires that new buildings have “nearly zero” net energy consumption by 2020. In Singapore, the Building Control Act enacted in 2008 aims to have at least 80 percent of new and existing buildings meet green standards by 2030. And France mandated in 2015 that all new commercial buildings must be partially covered with either a green roof or solar panels.
Building Codes in Action:
As early as 1992, the city of Freiburg, Germany, adopted a Low-Energy Housing Construction standard for all contracts in which the city sold land. When a cluster of former French military barracks was sold to create residential housing for 5,000 people, including many low-income residents, the standard went into action, and all homes were designed to consume no more than 65 kilowatt-hours of electricity per square meter. Some developers went further, building “passive houses” that lowered energy consumption to just 15 kilowatt-hours per square meter. This development, known as the Vauban district, is now considered one of the best examples of sustainable urban living.
In Freiburg’s Vauban district, building codes resulted in efficient home design. Photo: Ellen McArthur Foundation
Residents gather among energy-efficient buildings in Freiburg’s Vauban district. Photo: Sustainable Cities Collective
- Technology Mandates and Ordinances
Cities in China, Brazil, and Spain have been leading efforts to integrate solar thermal technologies into buildings. These solar water heaters do not require burdensome national or state government approval (they don’t face the same levels of permitting as, say, rooftop solar power) and are therefore easier for local authorities to implement. Combined with product certification standards to avoid the proliferation of low-quality equipment, technology-specific mandates are shifting urban energy consumption across entire cities.
Technology Mandates in Action:
Through a mandate, all new residential buildings in the Chinese city of Rizhao are required to include solar hot water technology. Today, this city with a population of 2.8 million counts 99 percent solar water heater use in the urban center (compared to just over 30 percent in the surrounding suburbs). Nine other cities in Shandong province also have adopted the mandate, and the province has supported efforts to deploy this energy-efficient technology by contributing research and development to create cost-competitive units.
In the Chinese city of Rizhao, development support and technology mandates have led to high rates of adoption of solar water heaters. Photo: Inhabitat.
A worker for the Tianpu Solar Power company completes the installation of a solar water heating array on the roof of a new housing development in Rizhao. Photo: Ariana Lindquist
- Green Social Housing
Cities can directly get involved in promoting sustainable buildings by integrating them with their efforts to provide social housing and improve local infrastructure. Green building and affordable housing are a logical fit, as efficient designs represent long-term savings for residents who are already struggling financially. In Europe, energy-efficient building designs and the use of renewable energy-based district heating systems can help the estimated 50 million to 125 million residents who are “fuel poor,” meaning that they spend more than 10 percent of their household income on heating fuel to stay warm.
Green Social Housing in Action:
Brazil’s Minha Casa, Minha Vida (“My House, My Life”) program has built nearly 4 million housing units for low-income families since its launch in 2009. Another 3 million units were scheduled to be built by 2018, but the country’s current economic crisis may thwart that goal. As part of the program, the government mandates specific environmental requirements, such as the use of rainwater collection systems and certified timber products. In the southern half of Brazil, close to 900,000 residents have benefited from compulsory solar water heaters through the program.
In the southern half of Brazil, close to 900,000 residents received solar water heaters when the Minha Casa, Minha Vida project made them compulsory. Photo: Adonias Silva/G1
Brazil’s Minha Casa, Minha Vida project has defined the environmental guidelines for 4 million low-income homes. Photo: Elói Corrêa/SECOM
Although cities are often at the forefront of green building efforts, current approaches are not yet sweeping enough to meet the broad environmental challenges we face. Municipalities increasingly may need to shift from voluntary measures to stronger mandates. Cities need to step in early to implement proper design before new structures are built, in order to secure decades of savings in greenhouse gas emissions and other impacts. Finally, cities will require the support of national governments to combine both bottom-up and top-down efforts to create a synergy of responses.
Cities need to step in early to implement proper design before new structures are built.
While promising, the current success stories are not yet enough to tip the global scale toward sustainability. But these experiences do show the transformative power of city representatives and the residents who elect them.
Gaelle Gourmelon is the Communications and Marketing Director at the Worldwatch Institute.
Michael Renner is a senior researcher at the Worldwatch Institute and the author of the chapter “Reducing the Environmental Footprint of Buildings.” His work has principally focused on two topics: the connections between environment and employment (green jobs and green economy) and the linkages between the environment and peace and conflict.
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