Selecting design strategies using multi-criteria decision making to improve the sustainability of buildings – sciencedirect electricity shock in the body

The building sector is one of the largest consumers of natural resources and energy in the world. Design strategies to improve the energy efficiency are a solution to increase the performance of a building. However, in most cases, such strategies are assessed only in the operational phase of a building. In order to evaluate the correct way to choose design strategies in buildings, they should be analysed taking into account a multidisciplinary approach based on sustainable development. The main objective of this paper is to propose a method that allows to choose design strategies more appropriate to lead to more sustainable buildings. Through the combination of building energy simulation, Life Cycle Assessment, Life Cycle Cost, indoor comfort conditions and a multicriterial decision-making method it is possible to choose the most sustainable design strategies to be applied in buildings.

The four parameters used to evaluate the design strategies in buildings are: the indoor thermal comfort hours obtained through the adaptive thermal comfort method, the energy demand over the life cycle, the carbon dioxide emissions over the life cycle and the monetary cost of the strategies over the life cycle. Furthermore, to investigate the effect of the climate change in buildings, the scenario A2 of the Intergovernmental Panel on Climate Change was used. To quantify these impacts, the Climate Change World Weather File Generator was used to produce weather data for future typical meteorological years, i.e., 2020, 2050 and 2080. The method was applied in two countries: Brazil and Italy. A single-family house located in three Brazilian cities was evaluated considering a 63-year lifespan. •

In this case study, twelve design strategies were analysed: four shading devices, two thermal insulations, two coating exterior walls, two roofs and two typologies of windows. In Italy, a multifamily residential building, located in Milan, was evaluated based on a 100-year lifespan. In this context, three different structure of the building were evaluated: X-Lam, reinforced concrete frame and steel frame. The EnergyPlus computer programme was used to estimate only the annual energy consumption for air-conditioning and the indoor comfort hours in the different cases of buildings. The energy and emissions life cycle of the design strategies were obtained through national and international databases. Different maintenance scenarios of the design solutions were also applied to verify their influence on the life cycle assessment. •

The reuse phase in the life cycle was analysed exclusively for informative purposes to verify the importance of it in the evaluation of the LCA. Finally, the prices of the different design strategies as well as the activities for its application were obtained through the Sistema Nacional de Pesquisa de Custos e Índices da Construção Civil (SINAPI) and the Camera di Commercio di Milano, respectively in the case study in Brazil and in Italy. The average inflation rate in the last ten years in the two countries was used to estimate the future costs. To analyse the four parameters used in this study, 30 traders of the construction sector from the region of Milan were selected to participate in the survey in order to set the criteria weights and determine their priority. The results showed that through the application of the proposed method it is possible to identify the most appropriate design strategies for more sustainable buildings. The effects of climate change on buildings are evident in the Brazilian and Italian case studies. In the Brazilian case study the results show that the design strategies that obtained a good energy performance in the operational phase, do not always provide an adequate behaviour in the four sustainability parameters evaluated. •

Among the three cities analysed, the design solutions applied in the building presented a different performance. In the two case studies evaluated in Brazil and Italy, the different data-bases used in the primary energy demand and carbon emissions parameters can significantly modify the final results for the selection of the project strategies. The adequate selection of the database is one of the main problems in the evaluation of LCA. Also, the application of the multicriterial decision-making method proved to be a useful instrument for selecting the best final design solution. In the Italian case study the results showed that the design solution with the highest level of sustainability was the reinforced concrete frame with rectified bricks. This study has demonstrated the need to apply the proposed method to ensure the correct choice of design strategies for more sustainable buildings. The method used can be applied in different types of buildings and locations. Through a more holistic approach to choose the design strategies in buildings we will improve the energy efficiency and the indoor comfort conditions by reducing emissions and financial cost.

The building sector is one of the largest consumers of natural resources and energy in the world. Design strategies to improve the energy efficiency can decrease the negative impacts of a building. In order to evaluate and select the most appropriate design strategies for buildings, they should be analysed through a multidisciplinary approach based on sustainable development. The objective of this study is to propose a method that combines adaptive thermal comfort, climate change, life cycle assessment, life cycle cost analysis and multi-criteria decision making to help selecting the best design strategies to improve the sustainability of buildings. The method presented herein is based on a system of indicators that allows a comprehensive evaluation of design strategies. A multi-family social building, located in Milan, northern Italy, was used as a case study considering a 100-year lifespan. Six design strategies were evaluated. The EnergyPlus computer programme was used to estimate the annual energy demand for air-conditioning alone, with and without the design strategies. Three different databases were used to perform the life cycle analysis. For the life cycle cost analysis, the cost of each strategy was estimated based on the pricelist of the Milan Chamber of Commerce ( Camera di Commercio di Milano). The results show that there will be an average increase of 53% in the cooling energy demand and a decrease of 49% in the heating energy demand in 2080 compared to the consumption in 2017. The design strategy with the highest level of sustainability was a reinforced concrete frame with rectified bricks, followed by a reinforced concrete frame with cellular concrete blocks and by cross-laminated timber (X-Lam) and wood fibre. This research highlighted the need for the use of a multi-criteria method to ensure the right selection of design strategies to obtain more sustainable buildings.