Concrete is the most commonly construction material used worldwide. In contrast to other countries, Ecuador lacks studies that determine the environmental impact of the production of construction materials. This research presents a quantification of embodied energy and CO₂ emissions associated with the concrete production, using as a case study a ready-mixed concrete plant in the city of Cuenca, Ecuador. The study was based on the Life Cycle Assessment methodology established by ISO 14040 and ISO 14044, and the 2006 Intergovernmental Panel of Experts on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories. The production of ready-mixed concrete was considered for one year, with a “gate to gate” approach including the “transport of raw material” to the concrete plant and the subsequent “transport of final product” to the construction site. The results revealed that to produce 1 m³ of ready-mixed concrete, its production required 568.69 MJ of energy, accompanied by 42.83 kg CO₂. Indirect transport generates the greatest environmental impact, especially the “transport of raw materials”, which represents approximately 80% of the embodied energy and 79% of CO₂ emission.

The Analytic Hierarchy Process (AHP) is a method that allows complex decisions to be made from impartiality, making it suitable for reaching a consensus among experts seeking to solve a problem. This method has been successfully applied in other investigations, and its use has been extended to several disciplines. This technical paper presents the lessons learned from a study that relied on the AHP method to determine priority aspects for sustainable neighborhoods. The research is developed in three replicable phases. In each of them, aspects that are recommended to be considered are detailed, for example, in the formulation of the hierarchical structure, selection of experts, expert survey design, and information processing for the determination of weights and levels of importance. • The utilization of software to apply the AHP method can help researchers to optimize time and resources. • Social networks proved to be more effective than conventional methods for identifying and contacting experts. • Subjective sustainability issues can be prioritized by expert consensus.

Resumen El cemento es un material indispensable para la construcción, por eso, obtener datos locales sobre el impacto ambiental que genera su producción en Ecuador es necesario para los tomadores de decisiones y fabricantes. Esta investigación determina la energía contenida y las emisiones de CO2 en el proceso de fabricación del cemento a partir de la aplicación de las metodologías del Análisis del Ciclo de Vida (ACV) y de las Directrices del Grupo Intergubernamental de Expertos sobre el Cambio Climático de 2006 para los inventarios nacionales de gases de efecto invernadero. El estudio considera la producción de una tonelada de cemento en un año de producción con un enfoque de “puerta a puerta”. Los resultados muestran que esa producción requiere 3.191,95MJ de energía y genera emisiones de 510,57kgCO2. Las contribuciones dominantes en energía se deben al consumo de caliza, fuel oil y electricidad. El proceso unitario que genera mayor impacto es la producción del clínker, tanto por las reacciones químicas que se producen en el horno como por su consumo de combustible.

Compared to the European Union (EU), Latin American (LA) countries are much slower in implementing policies to improve energy performance and thermal comfort in the residential building stock. This comes at a time when cities in developing countries are experiencing faster growth than in the developed world. Understanding that the morphological characteristics of the built environment are a key issue in improving the energy performance and thermal comfort of buildings allows for better decision-making in urban planning and design. However, this field has been relatively unexplored in LA. Therefore, this study proposes a workflow that integrates two urban models adapted to the particularities of LA cities (A+TUF): building archetypes (A) and typological urban forms (TUF). This will provide valuable information to architects, engineers, urban planners, and policymakers, to enhance decision-making processes. Considering the available information and the importance of the different parameters analyzed in the context of LA, 3 parameters are proposed for the definition of A and 9 for TUF. Additionally, 4 performance indicators are determined to assess energy performance (prioritizing passive design strategies) and indoor thermal comfort. Furthermore, the proposed workflow allows the incorporation of additional evaluation objectives related to other environmental aspects for holistic assessment. This will contribute to more sustainable urban planning in LA.

Esta investigación analiza el confort térmico de cuatro unidades de vivienda no climatizadas con diferentes sistemas constructivos, ubicadas en una zona rural andina de Ecuador sobre los 3000 m.s.n.m., para determinar estrategias pasivas de diseño. Para esto se describen características del entorno y constructivas de dos viviendas neo vernáculas con materiales naturales TRA-01 y TRA-02 y dos viviendas con materiales modernos CON-01 y CON-02. Se monitorizaron las variables de temperatura y humedad relativa exterior e interior durante 8 días, así como temperaturas de superficies de la envolvente y se evaluó el rango de confort mediate la temperatura operativa. Los resultados mostraron que tres viviendas presentaron temperaturas interiores estables, aunque solo la vivienda de fardos de paja estuvo parcialmente dentro del rango de confort. El estudio concluye que el aislamiento térmico de la envolvente, el diseño bioclimático y calidad constructiva son necesarios para mantener temperatura adecuada en estas zonas de clima frío.