Four Ways Cities Are Greening Our Buildings

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:

  1. 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.

Bullitt Center Living Building

The Living Building-certified Bullitt Center touts itself as “the greenest commercial building in the world.” Photo: Bullitt Center

Active Building Design Bullitt Center

Active design in the Bullitt Center encourages healthy activity. Photo: Taomeister

  1. 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.

Freiburg buildings

In Freiburg’s Vauban district, building codes resulted in efficient home design. Photo: Ellen McArthur Foundation

Freiburg market

Residents gather among energy-efficient buildings in Freiburg’s Vauban district. Photo: Sustainable Cities Collective

  1. 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.

Rooftop Rizhao solar

In the Chinese city of Rizhao, development support and technology mandates have led to high rates of adoption of solar water heaters. Photo: Inhabitat.

worker solar china

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

  1. 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.

Minha Casa Minha Vida

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

Entrega de 200 unidades habitacionais do Minha Casa, Minha Vida. Foto: Elói Corrêa/SECOM

Brazil’s Minha Casa, Minha Vida project has defined the environmental guidelines for 4 million low-income homes. Photo: Elói Corrêa/SECOM

What Now?

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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Michael-Small-2-150x150Michael Small, Executive Director at Renewable Cities writes on last week’s North American 100% Renewable Energy in Cities Dialogue in San Francisco. This article was originally posted on the Renewable Cities website.

Local governments in Europe have been leading the urban energy transition for years, but there’s a new trend emerging across North American cities towards 100% renewable energy.

Last week Renewable Cities, the Sierra Club, ICLEI USA, and the San Francisco Department of the Environment partnered to convene the first ever meeting of North American municipalities looking at transitioning to 100% renewable energy in at least one sector of energy use. Representatives of twenty American and Canadian cities and towns participated, from Oxford County, Ontario to San Diego, California.

100% renewable energy is a goal that seems like science fiction to the majority of North Americans living an urban lifestyle powered by historically cheap fossil fuels. Yet in the past two years, around twenty municipalities from the US and Canada, of different sizes and political outlooks, have passed resolutions to power their cities in the future using only renewable energy.

A few American cities have already achieved that in their electrical sectors, community-wide. Greensburg, Kansas and Burlington, Vermont are two examples. East Hampton, New York—at the tip of Long Island—should get there by 2020. More cities have plans to reach that goal by dates ranging from 2030 to 2050, for the most part just in the electricity sector. The City of Vancouver plans to reach 100% renewable energy in its heating and cooling and transportation sectors as well.

The motives for adopting a 100% renewable energy target are varied, and there is never just one explanation: usually it is a mix of responsible concern for reducing CO2 emissions, with the more pragmatic realization that wind and solar power are now cost competitive with fossil fuels in most states and provinces. Energy predictability and energy independence are two further motivators for local politicians across a wide political spectrum.

It’s not surprising that cities from the West Coast were well represented at our dialogue. San Diego, San Francisco, and Vancouver are the three largest cities in North America that have already made commitments to move to 100% renewable energy. Yet cities from the traditional manufacturing heartland of the US were well represented too, such Chicago, Pittsburgh, Cincinnati, and Cleveland. None of them have yet made commitments to reaching 100% renewable energy, but all were interested in learning more from other cities about how this could be done. The common realization from this dialogue was that reaching 100% renewable energy is to move along a continuum, in which setting a goal is just an early way-point.

One widely shared concern is the challenge of shifting large-scale and centralized utilities away from fossil fuels. Municipally-owned utilities tend to be much more responsive to community demand for cleaner energy. Cities that do not control their own utilities are starting to look at Consumer Choice Aggregation (CCA) as a strategy to encourage new renewable energy producers, including individual households, to start supplying their local market.

Yet we learned that even in the eight states where CCA is currently permitted, exercising that right can take years of negotiation and litigation with the prevailing utilities. For example, California has had CCA legislation on the books for ten years but San Francisco’s municipal utility has only recently been able to offer a “light green” 35% renewable option to consumers at par with the rates charged by PG&E (northern California’s largest private utility) and a “dark green” 100% renewable option for a marginally higher cost.


This leads to a second concern conveyed at our dialogue: How to ensure that the transition to 100% renewable energy is equitable in its benefits and costs in all three key energy use sectors (electricity, heating and cooling, and transportation).

In the electricity sector, large energy users typically can afford private renewable energy systems such as rooftop solar, and when they “defect” from the grid they take their contributions to capital costs with them. Those costs are downloaded to the remaining ratepayers, which can deeply impact lower-income households.

With respect to heating, we live in a world of cheap natural gas. North Americans do not yet have the economic motivation to save energy through deep energy efficiency retrofits of existing commercial, industrial, or multi-unit residential buildings.

In terms of transportation, until electric vehicles prove they make the most economic and practical sense, working families will continue to depend on fossil fueled-cars and buses. For these reasons, equity must be central to every city’s strategy.

Beyond concerns, we also heard many points of inspiration, such as from Lisa Jackson (former EPA Administrator and current VP Environment, Policy and Social Initiatives at Apple) about how one of the world’s most influential corporations is both pursuing100% renewable energy in its own operations and increasingly facilitating that goal along its entire supply chain.

Nicole Lombardo of Google also described Project Sunroof, which is a new platform that applies geographic data gathered aerially to indicate where and how solar installations could be positioned on rooftops. Working with data from local governments across the US, Google will generate instant estimates customized to specific buildings of the costs and benefits of installing rooftop solar.

I left San Francisco impressed by the degree of determination and innovation being shown by local governments. By the end of our three-day dialogue, it was clear there was not one concrete template for cities to follow in shifting to 100% renewables, but recipes for success had one common principle: With political will, cities can translate falling RE costs into opportunities to improve the quality of urban life.

The dialogue partners will be releasing a report on the North American 100% Renewable Energy in Cities Dialogue later this summer. Visit the project page for more information and subscribe for updates to be notified when the report is complete. We would like to acknowledge the California Clean Energy Fund and SunPower for supporting the dialogue workshop.

Michael Small is the Executive Director at Renewable Cities. This article was originally posted on the Renewable Cities website.

Images credits: Sierra Club/Laura Ferro

How Urban Dwellers Drive Massive Deforestation

This post is an excerpt from Worldwatch Institute’s Can a City Be Sustainable? (State of the World).

Urban centers lie at the root of an important—and often neglected—source of emissions: deforestation. According to Senior Researcher Tom Prugh in Can a City Be Sustainable? (State of the World), deforestation caused by growing urban consumption is contributing to massive emissions globally, despite increasing sustainability efforts locally.

Tropical deforestation accounts for an estimated 3 billion tons of carbon dioxide per year—equivalent to the emissions of some 600 million cars—according to researchers at Winrock International and the Woods Hole Research Center.

Deforestation in cities 1

Deforestation Drivers

Urban growth drives deforestation in at least two ways. First, as rural migrants to cities adopt city-based lifestyles, they tend to use more resources. Their incomes rise and their diets shift to a greater share of animal products and processed foods. This, in turn, drives land clearance for livestock grazing and fodder, either locally or in other countries that export such products or their inputs. Meeting the food needs of a rising and urbanizing global population could require an additional 2.7–4.9 million hectares of cropland per year.

“In Brazil, a surge of deforestation in the Amazon in the early 2000s has been attributed to the expansion of pasture and soybean croplands in response to international market demand, particularly from China,” writes Prugh. There, economic growth and diets richer in meat products have boosted soy imports from Brazil to feed pork and poultry.

Even in relatively highly productive European agriculture, it takes an estimated 0.3 square meters of farmland to produce an edible kilogram of vegetables, but 7.3 for chicken, 8.9 for pork, and 20.9 for beef.

Deforestation in cities 2

A second, and likely lesser, factor linking urban growth to deforestation is that cities are often expanding into areas of farmland and natural habitat, including forests. Cities worldwide are growing by 1.4 million new inhabitants every week. Urban land area is expanding, on average, twice as fast as urban populations. The area covered by urban zones is projected to expand by more than 1.2 million square kilometers between 2000 and 2030.

“Ironically, even as urban expansion drives forest clearance for agriculture, it simultaneously consumes existing farmland,” writes Prugh. “By one estimate, urbanization may cause the loss of up to 3.3 million hectares of prime agricultural land each year.”


What Cities Can Do

“The impact of urban expansion can, in principle, be attenuated by focusing on proven methods of shaping urban form to emphasize compact development and higher densities,” writes Prugh. Reducing consumption, however, is more complicated.

The first and most obvious option is to increase the efficiency of economies at delivering human well-being per every unit of resource input. The impact of the dietary share of higher consumption could be reduced sharply by reducing food waste and creating incentives for much lower meat consumption.

Cities also may have a role in determining broader agricultural policies. In addition to reducing meat consumption, it is possible to reduce the impacts of meat production by shifting from intensive, fossil fuel-based livestock systems to more-diverse, coupled systems that emulate the structure and functions of ecosystems.

Deforestation in cities 4

This post is an excerpt from Worldwatch Institute’s Can a City Be Sustainable? (State of the World). This report examines the core principles of sustainable urbanism and profiles cities that are putting them into practice.


Gaelle Gourmelon is the Communications and Marketing Director at the Worldwatch Institute.


Hundreds of Cities Commit to Combating Emissions

Through bold climate commitments, 228 cities around the world are taking the lead on climate action.

Over 200 cities have set greenhouse gas reduction goals or targets. Action in these urban areas, which represent a combined population of 439 million people, could propel countries to meet their Intended Nationally Determined Contributions (INDCs)—the national greenhouse gas reduction pledges embodied in the Paris Agreement. Continue reading Hundreds of Cities Commit to Combating Emissions

What is the Energy Future of Cities? 5 Expert Insights

Can cities shift their systems and structures to become sustainable? This is the first of two exclusive sneak peeks into our newest State of the World publication, Can a City Be Sustainable?, scheduled for official release on May 10, 2016. Join us for the launch symposium in Washington, D.C. or livestream online. Here we feature perspectives from five chapter authors: Richard Heinberg, Betsy Agar & Michael Renner, Gregory Kats, and Andrew Cumbers. Continue reading What is the Energy Future of Cities? 5 Expert Insights