As South east Queensland grows rapidly, a sustainable approach to development requires that the values of open space (including natural resources, habitat, landscape character, green belts and recreation) are protected. The sciences of conservation biology, landscape ecology, opportunity analysis and terrain evaluation can provide objective base data for determining significance (rarity, representativeness, sensitivity etc), and can inform the wider public, but cannot per se represent landscape quality and other values attributed to open space by the community. Effective land use planning needs transparent information regarding both objective and subjective significance of landscape and other environmental values. Environmental planning approaches which combine rigorous data survey and analysis with community involvement and review have been developed in South-east Queensland over the past 10 - 12 years, for both landscape and biodiversity. The paper presents regional assessment case studies of relative conservation significance (biodiversity, bushland and wetland habitat) and coastal landscapes (scenic quality) using reliable and flexible techniques for integrating scientific data with community values. The most successful approaches use 1st stage GIS mapping based on selected available data, reviewed by local or regional expert panels with community participation, to assign State, regional and local significance to mapping units, with a 'toolbox' of statutory and non-statutory measures to protect valued assets and control development in sensitive areas.