Many environmental behaviours involve a conflict between hedonic and gain goals versus normative goals; people often need to incur some costs to benefit the environment. Based on this assumption, we propose an integrated theoretical framework for understanding behaviour change that identifies two routes to encourage pro-environmental behaviour. First, the conflict between goals can be reduced by decreasing the (hedonic and gain) costs of pro-environmental choices. Although this route is important when pro-environmental choices are very costly, it may not result in sustained pro-environmental actions. Second, normative goals can be strengthened. This strategy may encourage pro-environmental actions, even when it is somewhat costly. We propose that the strength of normative goals depends on values and situational factors that influence the accessibility of these values. We discuss theoretical implications of our reasoning, and indicate how the integrated framework adopted in this paper may advance theory development and environmental policy making. (C) 2014 Elsevier Ltd. All rights reserved.