Figure 1: Commercial and residential floor space in China, the EU, Japan and the USA (2003) Source: WBCSD (2011)
Developmental challenges Developing countries are urbanising at a rate two to three times faster than developed countries, resulting in massive informal settlements and slums (UNEP, ILO, IOE, ITUC 2008). In the majority of the developing world, the scale of informal and low-cost housing is vast. In some cities, the informal city is bigger than the formal city. In Indonesia, an estimated 70-80 per cent of housing construction is informal (Malhotra 2003). In Brazil, more than half of all low-cost homes are built by the informal sector (UNEP SBCI 2010b).
In this context, providing affordable green housing for the poor is a considerable challenge when so many already face major economic barriers to afford conventional housing. Analysis of social housing, however, does not lead to clear results as to whether green social housing is more expensive at the point of construction; environmental design features may be but do not have to be, more expensive than the conventional features. For example, a detached social housing project Casa Alvorada (48.50 m2
) in the city of Porto Alegre, Rio
Grande do Sul, in Brazil, was 12 per cent more expensive per square metre than the typical housing solution of similar size implemented by the municipality, but still 18 per cent cheaper per square metre compared to another municipal typical model of about half of the floor area per unit (23 m2
) (Sattler 2007). Further, if the environmental
features are more expensive at the point of construction, they may yield benefits in terms of savings on water and energy during the occupation of the building.
Poverty and housing raises other unique challenges for sustainable building and construction in developing societies. Slums, be they informal settlements or run- down and overcrowded housing estates, are associated with social and environmental challenges including
lack of access to electricity, fresh water, health-care and effective waste management. Marginal locations poorly connected to public transport services are an additional obstacle in that they constrain access to employment opportunities (see Cities chapter).
Greening of buildings can be one of a series of strategies that improve access to basic services and reduce vulnerability and, more broadly, contribute to better living conditions of the poor. Facing this challenge, India, for example, is experimenting with three approaches, namely vernacular building (which focuses on local solutions and traditional knowledge), green building (supported by the internationally recognised Indian GRIHA rating systems, developed by TERI) and; energy- efficient building (focused on energy-use in commercial buildings) (UNEP SBCI 2010a). New approaches can contribute to providing electricity to the 1.5 billion people in the developing world currently living without it (IEA 2010a), and to lifting 100 million people from slum conditions and providing them with safe water and sanitation – a distinct Millennium Development Goal.
Cleaner and more efficient energy use will be critical to avoid any possible lock-in effect for poorer segments of society. Savings on energy costs can also free resources for investment in other basic needs. A recent study by the CSIR for the ILO (Van Wyk et al. 2009) provides several examples of energy-related projects in Africa: the installation of solar PV systems on schools, clinics and community centres in Zambia, the introduction of solar lighting and electricity into homes by local solar entrepreneurs in Malawi, the electrification of 60 health centres using solar energy in Mozambique, and the construction of windmills and solar-powered water systems as well as 10,000 improved cooking stoves for more than 250,000 people in Somalia.