Identification and analysis of risks in the sustainability assessment of housing.

Sustainability assessment is a means by which the advances towards sustainability can be measured.  In the UK one of the most commonly used assessments methods is the Building Research Establishment�s Environmental Assessment Method (BREEAM).  The domestic BREEAM, Ecohomes, has formed the basis of the 2007 Code for Sustainable Homes in England (CLG, 2007a). Ecohomes is used as a case-study of a sustainability assessment tool. This will allow the uncertainties in the assessment process to be seen and the ability of Ecohomes to assess sustainability appropriately and accurately determined. To ensure the most appropriate risk management techniques for application to sustainability assessment are used at each stage of the cycle a decision-support framework for selecting risk management tools in the built environment has been created. This has developed a visual approach and a case-based reasoning approach to the problem.  It has demonstrated it is possible to select appropriate techniques by defining the problem type in terms of political, economic, social, technological, legal and environmental.  The data used in a problem is categorised as fuzzy, incomplete or random. A comprehensive set of risks associated with the sustainability assessment of housing was identified using a combination of brainstorming and risk breakdown structure approaches.  These risks were validated and supplemented by issuing a questionnaire to housing sustainability assessors. A generic approach to analysing the risks in sustainability assessment was developed based on subjective probability and consequences to assess the risks.  This defined degrees of probability and consequence and a combination matrix outlined the overall severity of the risks.  The analysis was not only successfully applied to Ecohomes but also to a checklist for assessing the sustainability of a mixed use development (the SEEDA Checklist), the Code for Sustainable Homes and a sustainability assessment method for civil engineering projects (CEEQUAL). Risks from Ecohomes were also considered in further detail.