In densely populated regions such as Belgium where land is a scarce resource, nature areas are under increasing pressure of urban and infrastructural development. Decisions regarding land use changes usually do not fully account for the associated environmental impacts and the related social welfare changes. This paper aims to provide a generic monetary value function to assess the public benefits of amenity, recreation and biodiversity values associated with land use changes from agricultural land to different types of nature. This function can be used in cost-benefit analyses to inform decisions on land use changes, including the creation, restoration and compensation of nature areas. The ecosystem services values can be compared to the financial costs of such projects and accounted for in policy-making and planning decisions aimed at maximising social welfare. Important criteria for the development of this value function are that: (1) it should be transferable across sites and able to account for relevant characteristics of both the nature areas and the population of beneficiaries, and (2) it should control for spatial variables, such as size of the area and distance to the respondent's home. The value function of our case study is based on a large scale choice experiment, as part of a survey to capture public preferences, focusing on land use changes among a sample of 3000 households in the Flemish region in Belgium. In the choice experiment, respondents were asked to choose between different hypothetical nature development scenarios, described in terms of their ecological quality (nature type, species richness) and a set of spatial characteristics, including, size, accessibility, adjacent land use and distance to the respondents' residence. The model estimates are used to monetise public preferences for land use changes. The results show that the public attributes significantly different values to the different nature types, with highest values for forests. A distance decay effect was clearly observed, meaning that willingness to pay reduces when nature areas are situated further away from the place of residence. The size of the area was also significant but much less significant than would be expected. The application of the value function is demonstrated in two examples. © 2012 Elsevier Ltd.