The building sector currently accounts for 30-40 percent of global energy use. With continued population growth and economic development, building construction and operation will increasingly contribute to global climate change. However, a recent publication by the United Nations Environment Programme (UNEP) explains that significant greenhouse gas emissions reductions could be achieved with the right combination of government regulation, increased use of energy-saving technologies, and behavioral change. According to some conservative estimates, such improvements could reduce global CO2 emissions by 1.8 billion metric tons, which would more than fulfill current Kyoto Protocol obligations.
Baseline Data from UNEP
The building sector is an important aspect of the global economy, providing on average 5-10 percent of national employment and 5-15 percent of gross domestic product (GDP). 80 percent of energy consumption occurs during a building's operational phase (i.e. heating, cooling, and lighting), although the construction process is also important, particularly in rapidly industrializing countries such as China and India. In high-income countries, where fossil fuels are the primary energy source, the building sector contributes approximately 30 percent of total greenhouse gas emissions. This figure is more difficult to quantify in developing countries, where biomass (woodfuel, animal dung, etc.) is the primary energy source in low-income, rural areas.
Source: Davis Langdon, 2005
Greening the Building Sector
UNEP's recent publication, Buildings and Climate Change: Status, Challenges and Opportunities, illustrates numerous tactics to reduce energy use during both the construction and operation of buildings. A few examples include:
- Using recycled building materials. Studies estimate 12-40 percent of the total energy used to produce building materials could be saved.
- Designing durable and adaptable buildings, thereby reducing the energy costs of demolition and new construction.
- Improving thermal insulation by using airtight designs and thick, well-insulated walls.
- Increasing energy efficiency through energy saving appliances and intelligent lighting controls and thermostats, among other currently available technologies.
- Improving building design to maximize natural lighting, utilize renewable energy sources, or include natural ventilation.
- Introducing building codes and standards, which regulate physical, thermal and electrical requirements of building components.
Status of Building Standards Around the World (2000)
Source: Busch, 2000.
Challenges and Obstacles
The diversity of the global building sector makes it impossible to prescribe a universal solution. In developed countries, the primary challenge is to reduce energy use in existing buildings, whereas rapidly industrializing countries must focus efforts on new building construction. Overall, solutions must be tailored to the unique climate, economic and social conditions in a given country and to the local availability of material and technology.
RELATED LINKS:
UNEP Sustainable Construction and Building Initiative
Sustainable Buildings Industry Council
EarthTrends
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