The proposed definition of sustainable infrastructure in this paper is based on two main propositions. First, the sustainability of infrastructure must take into account the benefits and costs of the investment over the entire life cycle of the project, including all externalities, positive and negative. Second, sustainability must be assessed across all relevant dimensions. There is a long-standing agreement that sustainability must integrate the economic/ financial, social and environmental impacts of a project. The paper adds the additional dimension of institutional sustainability, given its importance for the other three dimensions and for the long-term effectiveness and impact of the project. In addition, the paper recognizes the more prominent role that resilience and technological innovation must play in the design
and operation of infrastructure assets given growing spatial vulnerabilities and the already evident impact of climate change. Finally, sustainable infrastructure must give special attention to preserving and rebuilding natural capital and to nature-based solutions.
The paper then sets out the detailed attributes that constitute the elements of each of these four dimensions and that together provide the framework for assessing the sustainability of an infrastructure investment.
Regarding environmental sustainability and climate resilience, the report states that “Sustainable infrastructure should (i) integrate climate and natural disaster strategies, (ii) preserve the natural environment, (iii) reduce pollution, and, (iv) optimize the use of resources”.
The comprehensive IDB Framework for Sustainable Infrastructure (prepared in collaboration with colleagues from Brookings and the Zofnass program at Harvard) is included as annex.