A healthy environment is an absolute necessity for the well-being of all organisms, including Human beings. However, a man who has reached the pinnacle of evolution is trying to bring about changes in the environment to suit his convenience. Unfortunately, this convenience is temporary. These negative changes to the environment are cumulating massively after the industrial revolution and have a counter effect on the environment. This course examines the relationships between building, site, landscape, and sustainability through the lens of ecology and systems thinking. Topics include basic concepts of global warming and climate system that are studied in this course. It will also introduce basic strategies of sustainable building design in different climatic regions through studying the vernacular architecture of a place and then how these strategies are articulated into the new design. The course ends up with a small project design to let students apply those strategies on a small-scale project.