natural compounds for building material manufacture can deplete these natural compounds from the earth. Moreover, extraction can cause harm to the natural habitat and biodiversity of the region where materials are extracted. Therefore, a project that uses minimum new building material and uses more of recycled materials is a more sustainable and responsible choice for a building material. Adaptive reuse potential According to Chusid's "urban ore" concept, existing buildings that are fast approaching dilapidation or disuse are a "mine of raw materials for new projects". Shen and Langston built upon this idea and said that "an even more effective solution than raw material recovery is adaptive reuse". They studied that "a huge focus on economic factors alone has led to the destruction of buildings well short of their physical lives". Shen and Langston developed an integrated model for the assessment of adaptive reuse potential by comparing case studies of one urban and one non-urban setting. The basis of this model lies in that "opportunity rises and falls within the confines of a negative exponential decay function linked to a building’s physical life expectancy". According to their study, a building reaches its maximum potential for adaptive reuse at a point when the building's age and its useful life merge or meet. At this point, the building's adaptive reuse potential is either an upward curve or a downward curve which can determine whether the potential is high, medium or low. The adaptive reuse potential calculator establishes a "predicted useful life" of a building by considering a series of physical, economic, functional, technological, social, legal and political characteristics. These characteristics are used to derive an "annual obsolescence rate" and "environmental obsolescence". These outcomes are necessary to determine an optimum point at which adaptive reuse intervention should occur. Obsolescence is advanced as a suitable concept to objectively reduce the expected physical life of a building to its expected useful life. A discounting philosophy is adopted, whereby the annual obsolescence rate across all criteria is the "discount rate" that performs this transformation. An algorithm based on a standard decay (negative exponential) curve produces an index of reuse potential (known as the ARP score) and is expressed as a percentage. This decay curve in buildings can be used to establish an ARP score, which is expressed in percentage. Cities can rank their existing buildings as per their adaptive reuse potential and this data can be used