Soluções construtivas para edificações - proposta de método de escolha baseado nos quesitos CO2 embutido e custo

Abstract

Greenhouse gas (GHG) emissions caused by anthropogenic factors have been increasing since the time of the Industrial Revolution, causing remarkable and harmful environmental impacts. Inserted in this context of environmental degradation, the construction industry is characterized by using traditional methods and is responsible for the excessive consumption of raw materials, non-renewable energy resources and waste production, making the sector responsible for a considerable portion of this contemporary global problem. The civil construction sector has relevance in the Brazilian economy and deserves attention regarding the potential for improvements in sustainability. The construction design stage is the one that adds the greatest chances of making correct decisions that affect the entire useful life of the buildings. Different constructive solutions are presented for the same stage of work, with different environmental footprint and cost. The present work presents a methodology to help the process of choosing materials and constructive solutions, taking into account the environmental aspect, through the quantification of embodied CO2, and the economic viability, through the calculation of costs. For this, an electronic spreadsheet is used that compares materials used in six constructive stages - wall, floor, roof, doors, windows and structure - plus a new functionality, the financial aspect. The methodology assigns weights to the environmental and cost aspects, in order to create scenarios with scores that can meet the wishes or needs of the designers. The results obtained in a case study showed the methodology in practice and, for the chosen project, the scenario of balance between the requirements proved to be the most applicable, since the exchange of solutions with more privilege for the environment represented an increase in proportionally large cost. The introduction of the cost factor in the spreadsheet used in the work represented an advance in the computational tool developed at the Faculty of Engineering of the UFJF.