Given the accelerated urbanization process throughout the twentieth century, many of today’s cities reflect a fast and disordered growth, which influences directly the demand for natural resources. For an indispensable change in the current urban infrastructure management models, it is necessary to quantify the sustainability level of actual practices and proposals. In this context, based on widespread methods, SBTool_PT Urban Planning represents an adaptation of the SBTool international method to the Portuguese context. This tool assesses the sustainability level of the practices promoted in urban projects with no size restrictions and is applicable to new urban development and/or urban renovation. The process is conducted by a rigorous analysis of requisites specifically developed to stimulate improvements on energy consumption, management of potable water, solid waste, urban soil and territory and air quality. Aiming at a full introduction of the tool, this article contextualizes its development and characterizes its assessment methodology. Additional application to a case study shows how the assessment of a proposed project is performed. It is intended to demonstrate in which way sustainability assessment methodologies allow the promotion of innovation and urban sustainability through the environmental preservation and the improvement of the quality of life in urban areas.