Ecosystems and Sustainable Urban design Nexus – A Borderless Concept, Published in the Global IIT2005 alumni Conference publication on ‘Beyond ii Technology with the theme Technology without Borders’ May 20-22 2005, Bethesda, Washington DC, USA, 105-111 Eco-systems and Sustainable Urban Design Nexus – A Borderless Concept By Dr. Qazi Azizul Mowla Abstract Open spaces are an important element of built environment, which provides vibrancy and sustainability to a city. An Ecological approach to design and manage these spaces is crucial to the sustainability of urban environment. Green grids or Green Urban Corridors, Green Urban Pockets or Vegetated Roofs and water bodies, are general approaches to mitigate some of the losses of the natural systems in an urban area. Eco-systems and Sustainable Urban Design Nexus – A Borderless Concept By Dr. Qazi Azizul Mowla Professor Department of Architecture Bangladesh University of Engineering and Technology, Dhaka qmowla@yahoo.co.uk Introduction Crisis in the built environment has prompted the planners to come up with the concept of ‘Eco- Design.’ It does not reject high technology, but it is based on an ecological moral imperative – takes less from and dumps less into the environment. [5] Any space in an urban area outside the buildings constitutes urban open space. And the design and management of these spaces, are crucial to urban sustainability. Urban Sustainability Open green spaces in the city, with their cooling effect function like lungs. These open green spaces can also be used as active recreational areas for its residents. Circulation areas although serving active purposes, provide some breathing space to the urbanites, where traditionally the roads and lanes act as socialization spaces. The image of South Asian Cities, derives from its people the pattern of spaces and activities, therein the relationship between the living and non- living part of its environment, time, space and the people. It does not have to be a concrete element. Natural elements such as plants or bodies of water, can very well serve this purpose [6]. Also, nature has a role to play to combat social and physical pollutions.