Design approaches to prevent/reduce construction and demolition waste generated through the building life processes and a model suggestion

Increased construction activities along with the increasing population in Turkey and the world lead to growing environmental problems, because buildings generate waste through the building life processes (construction, usage and deconstruction/demolition). Disposing of this waste into the environment causes soil, air and water pollution. The large volume of construction and demolition (C&D) waste strain waste sites and negatively affect living and nonliving environments. Moreover, it is more difficult to dispose of C&D waste than domestic waste since it contains harmful substances such as asbestos, lead and volatile organic compounds. Therefore, the fundamental task of C&D waste management, a top priority waste stream, is prevention/reduction. If the amount of waste that is collected, processed and eliminated is reduced, environmental and economic costs can be reduced. Preventing/reducing waste generation is the most effective method for stopping the depletion of natural resources and is an essential factor in environmental conservation and the sustainable use of natural resources. The greatest responsibility in preventing/reducing C&D waste belongs to designers, who make decisions directly in the design of the building and directly and indirectly in the construction, usage and deconstruction/demolition phases. This study examines the ways that C&D waste can be prevented/reduced in the design phase, develops a design approach and proposes solutions. The study consists of seven chapters. The first chapter offers definitions for C&D waste, compares the amounts of such waste in different countries and describes how this waste is generated. Studies conducted in Turkey and the world on preventing/reducing the waste generated in the construction, usage and deconstruction/demolition of buildings are examined. The importance, objectives, methods and scope of the study are presented here. The second chapter examines the sub-phases of designing the building. The importance of the design phase in terms of the waste generated in construction, usage and deconstruction/demolition is also explained in this chapter, which determines the scope of the study. In the third, fourth and fifth chapters, relationships between design and construction, design and usage, and design and deconstruction/demolition phases are described, in light of the knowledge that waste is created in all these phases by design decisions. Suggestions are offered for managing the waste generated throughout the lifespan of the building during the design phase, and "designing out waste criteria" are presented. The sixth chapter of the study presents a model that designers can use to prevent/reduce C&D waste. The theoretical conclusions are presented here as a flow chart. The seventh and final chapter of the study is entitled "Conclusions and Assessments." It evaluates this study's design approach for preventing/reducing the waste stream generated in buildings' construction, usage and deconstruction/demolition phases. Keywords: C&D Waste, C&D Waste Prevention/Reduction, Construction Phase of Buildings, Usage Phase of Buildings, Deconstruction/Demolition Phase of Buildings