This paper is looking at European environmental policy from the "second image reversed" perspective. Specifically, it investigates the conditions under which we see administrative change in the EU member states as a consequence of the implementation of EU environmental policies. We adopt a comparative research design analyzing the impact of four environmental policies in Britain and Germany to trace the conditions for adaptation in the context of different administrative structures and traditions. As a starting hypothesis we adopt the institutionalist expectation that administrative adaptation depends on the "goodness of fit" between European policy requirements and existing national structures and procedures. On the basis of our empirical evidence we further refine the notion of "goodness of fit" by looking at the level of embeddedness of national structures in the overall administrative tradition from a static and dynamic perspective. Furthermore, we develop an explanatory framework that links sociological and rational choice variants of institutional analysis.