There is increasing recognition that social and ecological challenges necessitate societal change. In responding to these challenges a number of tools have been mooted as having the potential to facilitate change at the organisational level. Accounting is one such tool which is implicated in changing the mental models of those making decisions in organisations (Bebbington, 2007a). However, the role that accounting performs is uncertain and calls have been made to extend our understanding by exploring further empirical cases (Bebbington, 2007a, 2007b; Bebbington, Brown and Frame, 2007a; Bebbington, Brown, Frame and Thomson, 2007b; Tilt, 2006) in a way which can make explicit a priori assumptions of change (Broadbent and Laughlin, 2005). Experimenting with social accounting technologies may provide greater insight into their limiting and enabling aspects. Examples of such technologies include full cost accounting (FCA), the sustainable cost calculation (SCC) and, most recently, the sustainable assessment model (SAM). The SAM is an accounting technology developed to incorporate sustainability considerations into organisational decisionmaking and, potentially, accountability processes. In constructing and implementing new accounting technologies such as the SAM, researchers are confronted with two key challenges: first, a lack of empirical exploration within field studies means the impact a new technology may have is not well documented (Gray, 2002); second, the extant theorisation with which to evaluate 'successful' implementations remains underdeveloped (Gray, 2002). For example, use of non-explicit evaluative criteria glosses over the necessary aspects by which people can facilitate and evaluate change (Thomson and Bebbington, 2004, 2005; Dillard, 2007). This thesis explores the potential of the SAM to foster more critically reflective organisational accounts in the pursuit of sustainability, and involved the application of the SAM in two New Zealand case-study sites. In total, forty-seven individual and group semi-structured interviews were conducted over a three-year period. The resulting empirics provided the basis of an organisational narrative, structured according to Laughlin's (1991) organisational change framework, and evaluated using a Freirian heuristic. Laughlin (1991) provides a framework that sensitises the researcher to identify facets of change considered salient in the application of the SAM. His framework provides a structure for the organisational narrative (that is, both a 'technical' account on how the SAM was applied and a descriptive account on what specific change may have occurred in the organisation). However, drawing on Laughlin's (1991) framework presented two key challenges: first, the SAM requires a critical evaluation framework that makes explicit a priori assumptions of change that are not evident using Laughlin's (1991) 'real' and 'superficial' change categorisation; second, the skeletal nature of the framework focuses insufficient attention on how change occurs (Laughlin, 1991, p.229).…