Changes in planning practices can be explained from the prevailing theoretical juxtaposition of 'institutional design' and 'institutional evolution'; two schools of thought that are at the extremes of assumptions on modifi ability. The two extremes are considered to be inextricably linked to each other and cannot be separated; institutional design at a higher level highly infl uences institutional evolution at a lower level. In this paper we add the opposite direction of their interdependence. We found that small and sometimes even unexpected efforts of institutional design at a low level of scale can, when aggregated, result into an evolution of collective institutions at a higher level. We participated in a cooperative project between research and practice, which was established as an exchange project on innovation in land development. We investigated the genesis of institutional change in land development, which is a specifi c regional planning instrument. We analyzed 40 planning practices that were presented by land agencies from seven EU regions (Flanders, the Netherlands, North Rhine-Westphalia, Galicia, Portugal, Hungary, and Lithuania) as their most innovative ones. We studied the histories of 14 of them intensively, using grounded data gathered in visits, discussions, and in-depth interviews with key persons. We found great similarity across these 14 cases in terms of the distinctive patterns relating to local processes leading up to systemic innovations: seemingly small, local, often unexpected and unpredictable occurrences appeared to have set the process of innovation in motion. The evidence demonstrates the relevance of the landscape metaphor found in theories on Complex Adaptive Systems for understanding institutional change in planning practice.

Why do societies implement land policies? A number of arguments have been put forward in the literature, ranging from economic conceptions based on market failure and the problem of negative externalities to a more social conception based on welfare distribution and collaborative planning. However, neither all societies with similar market failures or negative externalities develop and implement land planning nor implemented land planning always results from collaborative planning. The arguments found in the literature seem not to fit the reality and, in most cases, cannot explain why societies create or undertake innovations in land planning. Within the framework of institutional change theory and based on the analysis of the emergence of two land planning devices-a land use law and a land banking law-in Galicia, Northwest Spain, this paper argues that land planning is developed to tackle negative outcomes of former institutional setups. However, the negativity of such outcomes is measured not in terms of economic performance, but in terms of social acceptance. The search for a workable definition of property within the Galician society seems to be the main driver of institutional change in land use planning analysed in this paper.