An alternative approach to conceptualizing and measuring the built environment is developed which forms the basis of a new assessment tool. The role of buildings is reframed to consider what capabilities for sustainability a building can provide to the inhabitants and local community. This capability to support sustainability is defined as the ability to improve the local quality of life (Human Development Index) whilst remaining below the environmental carrying capacity (environmental footprint). This approach has clear implications about the role of buildings in enabling residents and users to achieve these targets and outcomes. This shifts the focus of net-positive development toward configurations and characteristics of the built environment that are appropriate for a particular context. A Built Environment Sustainability Tool (BEST) is presented that defines and assesses these configurations and characteristics. Assessments can be conducted by measuring the extent to which required configurations and characteristics exist (i.e. ‘the capability of the built environment to support sustainability’). BEST is compared with other green building rating tool approaches in order to review the methodology critically and to evaluate this as a means of improving built environment sustainability performance.

Carbon emission scenarios are used as key inputs to the sustainability and built environment strategies and policies of many developed countries. Decisions and direction in these are based on carbon emission models which show the optimum mix of interventions required to achieve carbon emission reductions or stabilization. Developing countries and countries in Africa are now under increasing pressure to adopt carbon emission criteria as the key focus of their built environment policies and strategies. This paper argues against this. It suggests that focusing on carbon emissions is likely to result in limited resources and timeframes being exhausted trying to achieve reductions and valuable opportunities to build long term sustainable solutions will be lost. It also argues that increasingly scarce resources, infrastructure backlogs, the lifespan of infrastructure and buildings (50+ years) and the limited timeframes for addressing climate change mean that African countries cannot address carbon emission reductions first, and then address sustainability later; they need to address both at once. This paper also argues that while reducing carbon emissions may benefit companies involved in renewable energy and energy efficient technologies, it does not lead to sustainability. Sustainability is complex and requires the achievement of minimum quality of life standards as well as a balance between environmental and human systems. Carbon emission reduction technologies, by themselves, will not achieve this. This paper draws on a definition of sustainability developed by the World Wildlife Fund to show how a sustainable development approach can address carbon emissions while building more sustainable systems. It describes the Built Environment Sustainability Tool (BEST) developed by the author in 2011 and shows how this can be used to assess built environments and identify appropriate mixes of interventions to improve the sustainability performance of built environments. It also outlines interventions that can be used to support the development of more sustainable African built environments.