The concept of adaptation constraints has become well known in the climate change literature. It describes impediments to the process of adaptation that could in principle be overcome but often are not. Many adaptation constraints have been identified and described in the literature across a wide range of contexts, and the importance of their influence on climate change adaptation is clear. However most studies have focussed on describing constraints rather than exploring their origins, processes, and possible impacts. As a consequence, it has been difficult to operationalise the concept to provide information meaningful to decision makers. This study demonstrates an approach to estimating empirically the processes and the impacts of adaptation constraints, based on a case-study of farmers in New Zealand. It combines established social scientific methods to explore the processes underlying a range of adaptation constraints and estimate the impacts that these constraints may have. The approach can be used to explore further the social and economic impacts of adaptation constraints. This information can then be used to consider sub-optimal adaptation to climate change more fully, and paves the way for policy responses that are more conscious of the human elements of climate change adaptation.