This thesis discusses a method of analysing the input of interventions in a building's site design, all of which affect the heat island effect, bio-diversity and hydrology of urban areas. Existing standards from Toronto, Vancouver and Berlin have been researched and analysed. This paper presents an evolution of a method called biotope area factor used in Berlin, Germany. A synthesis of the approach of all three systems was considered and distilled into the key points which were then incorporated into the proposed method. In addition to the impact of an individual building, it also includes the impact from the adjacent street area. The final components of this thesis are the application of the method developed to an urban area in the city of Toronto and results showing the impacts on architectural design from site rating systems.