An increasing attention has been given in the last fifteen years for sustainable buildings. This interest took potential due to the evidence, from a variety of research works, of the large contribution of the built environment to the global energy consumption, green house emission and/or resource depletion. Many national and international organizations focused on the sustainable built environment (i.e. the Green Building Challenge (GBC) in Canada, the British Research Establishment, the Finland Building Information Institute and the USA Green Building Council). Several tools were developed, as a result of the effort of these organizations and others, as well. These tools vary in their methodologies, target users, target building types, and scopes of application. Some are just auditing tools (i.e. BEPAC, EcoPoints, and LEED), others are simplified design aid tools (i.e. Eco-Quantum-domestic and the Green Guide), and the rest are more advanced design aid tools (ATHENA, BEES, BREAM and Eco-Quantum-Research). This paper presents a comparative study of the available tools, looks at their current development efforts and discusses the future of such tools from building designs' perspective.