An estimated 100 billion square meters of new construction is expected in countries without mandatory building energy codes. A consistent set of principles can frame the work needed to shape thriving, low-carbon cities.
A century ago, the world was largely rural. Today, construction of tall skyscrapers and low-slung buildings is expanding cities from Accra to Zurich. Buildings anchor two systems—energy and urban mobility—and drive economic growth. At the same time, carbon dioxide (CO2) emissions from buildings are directly responsible for 50 percent or more of an urban area's total carbon footprint. Within this widespread and extraordinary impact lies tremendous potential for cities to shape the future.
In some parts of the world, the buildings of the future are already largely built but in need of renovation. In other markets, new construction will be transformative. Global building square footage is projected to double between now and 2050. In many of the places likely to see huge increases in construction, building energy codes, which guide the long-term energy and carbon impact of buildings, are not in place.
The global building boom will shape the economic prospects as well as the health and well-being of current and future urban residents. Low-carbon buildings—those that pair high energy efficiency with renewables and emit little or no net carbon—have the potential to reduce global building energy use by 50 percent and CO2 emissions by 84 gigatonnes by 2050. Global energy-efficiency improvements alone could lead to monetary savings of between $360 billion and $530 billion. Across all economies, low-carbon buildings are linked to health by reducing outdoor and indoor air pollution, improving comfort and well-being, and reducing risks from climate change.
Building codes and standards are a foundation of this transformation. From mandatory base codes to pioneering innovation standards, requirements and incentives define new building construction and existing building renovation. These guidelines can influence many of the critical decisions made in early design phases that determine building energy use and carbon impact, directly shaping the energy needed to heat, cool, and operate a building as well as the energy used in transportation. Codes and standards also push for improvements to ongoing operational performance and can address embodied energy, or energy emitted during material production, onsite construction, and final demolition and disposal.
But while the potential of building energy codes to reduce emissions is clear, they are not as strong or widespread as buildings themselves. An estimated 100 billion square meters of new construction is expected in countries without mandatory building energy codes. A consistent set of principles, however, can frame the work needed by city governments and their public, private, and nonprofit partners to shape thriving, low-carbon cities.
Across markets, building energy codes must be established, strengthened, and enforced. New and bolder codes must take root to foster deeper carbon reductions across all phases of a building’s life span. To make significant progress, cities must pair these efforts with policies that link buildings to sustainable mobility solutions and a decarbonized electricity supply—and they must look to collaborate with other levels of government and the private sector.
It is no easy task, and it is one that will require tailored actions and strength across cities and markets—but the benefits will reach every corner of society, from the economy to human health, today and for decades to come.