Sandra Monteiro Silva

Comparing cost-optimal and net-zero energy targets in building retrofit

The recast of the European Unions Energy Performance of Buildings Directive introduced the concept of nearly zero-energy buildings, requiring its adoption from 2021 by all new buildings and existing ones submitted to major renovations. European Union member states must also ensure minimum energy requirements for buildings in order to achieve cost-optimal levels during their life cycle. Cost optimality and nearly zero-energy buildings are important concepts in European Union energy policies. These concepts are related, but one is more focused on costs, while the other is more concerned with low energy consumption and on site-renewable energy harvesting. If these approaches result in major differences in the selection of the best package of retrofit measures, then the transition from the cost-optimal concept to nearly zero-energy buildings might be problematic. To assess the most cost-effective solutions to achieve net-zero, a building in Porto, Portugal, was analysed. This determined not only the most cost-effective retrofit solutions but also compared these net-zero solutions with those resulting from the cost-optimal calculation. Both approaches lead to similar results, indicating that the transition between ‘cost optimality’ to ‘nearly zero-energy buildings’ could occur in Portugal.

Operative Conditions Evaluation for Efficient Building Retrofit—A Case Study

The implementation of energy efficiency measures into the existing building stock is essential to meet the 2020 targets set by the European Union (EU) Energy Performance of Buildings Directive (EPBD) and reinforced with the “EPBD-recast”. Thus, energy refurbishment of existing buildings is fundamental to achieve these goals. However, energy issues should not be the only concerns since the indoor environmental quality (IEQ) is also as important. When planning a building retrofit it is then necessary to consider the energy efficiency requirements as well as the IEQ. To do so, the main problems of the existing buildings should be identified. This work presents a study carried out in a large office building to identify the main pathologies related to the energy efficiency and to the IEQ. The main objective of this study was to characterize the actual situation of a building that represents a great number of the Portuguese office buildings in order to identify the principal problems that occurs in this type of buildings, to support the development of a refurbishment project of the building that can optimize both the energy efficiency and the relevant parameters to the IEQ and that are also solutions with potential to be used in other buildings.

ATRIBUTOS FÍSICO-QUÍMICOS DO SOLO EM UMA VOÇOROCA NO MUNICÍPIO DE BRASIL NOVO – PARÁ: UM ESTUDO DE CASO

Due to the activities related to the abundant agricultural use in the rural areas of the municipality of Brasil Novo, in the State of Pará, the soils of the region are degraded and later compacted, due to the lack of adequate management. In this case study, the objective was to evaluate the physical and chemical attributes of a voçoroca located in a rural property in the municipality of Brasil Novo. Deformed and undisturbed samples were collected to determine the chemical and physical properties of the soil, comprising the upper area (A), the middle area (B), the lower area (C) and the area with natural regeneration (D). For the statistical analysis of the chemical attributes the Wilcoxon test was applied. In the evaluation of the physical attributes it was verified the high density of the soil (Ds). The inadequate use of the area together with the erosive processes highly influenced by the topography of the land, promoted low soil fertility, presenting low levels of macronutrients (P, K+, Ca2+ and Mg2+), high saturation by aluminum, high acidity and low sum of bases and cation exchange capacity in soils of the evaluated areas. In the statistical analysis, it was observed that a significant difference occurred only in the comparison between areas A and C in the depth of 0 to 20 cm, as a function of nutrient transposition by the leaching process. The results indicated the need to use adequate practices for the control of erosion and the restoration of soil structure.

Optimization of the sustainability during the refurbishment design phase of a residential building using SBToolpt-H

As it has been observed along the years, the unsustainability of the built environment is due to the high resources consumption and low indoor air quality of the existing building stock. In order to support the sustainable refurbishment design of buildings, and to meet European goal to achieve nearly zero-energy consumption standards in buildings in 2020, it is urgent to define guidelines that can be implemented since the earlier stages of the design. This paper defines guidelines to optimize the sustainability of a residential building and presents the process of sustainable building refurbishment, applied to a case study. To achieve this goal, the definition and evaluation of a group of procedures to be implemented, and a cost-benefit analysis applied to a case study was performed.

Avaliação da sustentabilidade de soluções de reabilitação energética para coberturas de um edifício de habitação

A construcao de novos edificios, infraestruturas e a reabilitacao deve reger-se pelos principios de desenvolvimento sustentavel. A reabilitacao de edificios pode contribuir para uma melhoria do desempenho ambiental das cidade e da qualidade de vida dos seus cidadaos. O presente trabalho tem como finalidade otimizar, sob o ponto de vista de eficiencia energetica e sustentabilidade, a solucao de reabilitacao a aplicar na cobertura de um caso de estudo. Para a avaliacao do nivel de sustentabilidade de diferentes solucoes de reabilitacao da envolvente vertical exterior dos edificios, isto e do seu nivel de desempenho global baseado em indicadores ambientais, sociais e economicos, sera utilizada a Metodologia de Avaliacao Relativa da Sustentabilidade de Solucoes Construtivas (MARS-SC). Os resultados obtidos neste estudo resultam da aplicacao da referida metodologia a um caso de estudo. A aplicacao a um caso de estudo, correspondente a um edificio unifamiliar convencional em Portugal, permitiu avaliar a influencia da solucao de reabilitacao nos impactes ambientais incorporados, no consumo de energia e nos custos de operacao.