The growth of a city is linked to the population growth and the mobility and the lifestyle demand of the inhabitants. These put pressures on the available resources, making distribution of them inequitable. Available resources are not only scarce but the blown or consumption of these resources produces wastes. These are issues that have not been successfully addressed by most cities. As a result, cities surreptitiously fall into decay. This paper draws explicitly on sustainable cities to identify some key issues and principles of urban design that constitute sustainable development. Sustainability is taken as referring to global ecology, and development is recognized as being much resource broader than economic growth. Sustainable development is therefore about maintaining and enhancing the quality of human life - social, economic and environmental -while living within the placed carrying capacity of supporting ecosystems and the resource base. The two key principles that emerge from this definition are first, effort at satisfying human needs, recognizing the obligation for interregional human as well as intra-regional equity; and second, increasing the level of self-sufficiency at different scales - buildings, locality, town, region. From an ecological and thermodynamic perspective, cities are increasingly concentrated nodes of consumption within an increasingly human-dominated global landscape. Hence, it is without doubt that material consumption is at the heart of the patterns sustainability crisis of cities. Thus, this paper will seek to look at the factors of sustainability of a city by referring to the environmental scenarios of the city of Kuala Lumpur, to understand the ecologic imperatives of city planning.