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Energy is crucial to the wellbeing and development of nowadays society and will remain important for the foreseeable future. With respect to the type and quantity of energy consumed, significant changes are ongoing and further major changes can be expected in the near future. There are also various policy objectives that shape energy policy, depending on the country context. Among these objectives, the following can be highlighted: minimizing any adverse effects on the climate and on the environment; providing energy access to all; securing energy supply; reducing dependence on energy imports; looking for new energy sources, routes and suppliers that offer local economic benefits; reducing local environmental pollution; driving job creation; achieving low energy costs for society. Key strategic elements to reach such objectives are in particular the gradual transformation of the energy systems from fossil fuels to renewable energy, the increase of the efficiency of the energy systems, the reduction of energy use by consumers, the creation of fully integrated energy markets and the removal of unnecessary regulatory or technical barriers. The information provided in this guidebook aims to contribute to the reaching of the above-mentioned policy objectives. The guidebook is based on the results of a research project carried out within the IEA Energy in Buildings and Communities Programme (EBC) called "Cost-Effective Energy and Carbon Emissions Optimization in Building Renovation (Annex 56)". The guidebook was compiled to raise awareness among the players that can influence policies and standard definition and to engage them in the subjects of energy efficiency and renewable energy sources in the context of building renovation. Existing buildings present a tremendous potential, not only to reduce energy use and emissions, but also on other areas of the political agenda. It is the objective of this guidebook to highlight how energy related building renovation is a policy tool to achieve broad benefits to society., info:eu-repo/semantics/publishedVersion

This guidebook was compiled to raise awareness among the players that can influence policies and standard definition and to engage them in the subjects of energy efficiency and renewable energy sources in the context of building renovation. Existing buildings present a tremendous potential, not only to reduce energy use and emissions, but also on other areas of the political agenda. It is the objective of this guidebook to highlight how energy related building renovation is a policy tool to achieve broad benefits to society, info:eu-repo/semantics/publishedVersion

This guidebook is particularly intended for professional home-owners, i.e. individuals or companies that own and manage residential buildings. It is assumed that these owners are responsible for ensuring maintenance, repair and general servicing tasks and lead the decisions on the improvements to be made regarding comfort, safety, saving energy or just uplifting the buildings to contemporary needs or style. The main goal is to help in the decision-making process towards the optimized renovation of the residential building stock. More specifically, the guidebook provides a framework for the understanding of the relationships between cost-effective building renovation, energy savings and the use of renewable energy sources, highlighting the total added value achieved with the interventions., info:eu-repo/semantics/publishedVersion

The relevance of the building sector in the global energy use as well as in the global carbon emissions makes the improvement of the overall energy performance of existing buildings an important part of the actions to mitigate climate changes. Regardless of this potential, large-scale building renovation has been found hard to trigger, with present standards mainly focused on new buildings, not responding effectively to the technical, functional and economic constraints of the existing ones. One of the common problems in the assessment of building renovation scenarios is that only energy savings and costs are normally considered, despite the fact that the investment on energy efficiency yield several benefits beyond the value of saved energy (the so-called co-benefits). To demonstrate and highlight the relevance of co-benefits achieved in the renovation process, a Portuguese neighbourhood with nearly 17.000 inhabitants that has been recently renovated is analysed in search for evidences of the existence of these co-benefits and their relevance. Indoor temperature, humidity and noise insulation were monitored and a survey to the residents was carried out. Results clear indicate the achievement of co-benefits at the building level such as increased user comfort and reduced problems with building physics (mould and water infiltrations), but also the elimination of the feeling of gentrification by outside people to the neighbourhood. The analysis demonstrates that the decision-making process canâ t only be based on investment costs and energy savings, being necessary that owners, investors, promoters, but also policy makers adapt their reasoning to include these additional benefits.

ISBN 978-85-92631-00-0, Glazing contributes significantly to heat transfer between outdoor and indoor spaces and these surfaces act directly on daylighting and thermal comfort. Based on these aspects, spectrophotometric characterization of double glazings was accomplished to study components for a modular facade system for the climate of Portugal. This study focused on results of spectrophotometric measurements of optical behavior in the different solar spectrum intervals ultraviolet, visible and near infrared, specifically transmittance of two types of double glazings. The first double glazing presents a single pane of green glass with a solar control foil and a single pane of a glass with an extremely low-emissivity foil; the second one presents a single pane of self-cleaning glass and a float clear annealed glass. Results show the percentage of transmission to spectrum intervals, which enabled the verification of the efficiency of the glazing in terms of daylighting and the correlation to thermal performance. These results generate subsides and indications for specification and adequate uses of transparent surfaces, and also complements the datasheets available from the manufactures., Erasmus Mundus ISAC - Improving Skills Across Continents

The recast of the energy performance of buildings directive stipulates that by 2020 all new buildings should reach nearly zero energy levels (2019 for buildings owned or occupied by public authorities). Therefore technicians involved in the design, conception and approval of such buildings should be able to understand and apply nearly zero energy buildings (nZEB) concepts both towards new buildings and the refurbishment of existing ones. However the number of architects and engineers that are able to deal with new technologies and standards might not be adequate to the increasing market demand. Additionally, at European Union (EU) level there are differences in commitment to the EU targets and the construction of nZEB. In this context, arose the SouthZEB project, that is an Intelligent Energy Europe (IEE) funded project, that aims to fill this gap and address the need to develop training schemes to professionals involved in nZEB building process, transferring successful practices and knowledge from front runners to target Southern EU countries that are less advanced in this area. This paper presents the project aims and overview.

The building sector is one of the Europeâ s main energy consumer, making buildings an important target for a wiser energy use, improving indoor comfort conditions and reducing the energy consumption. To achieve the European Union targets for energy consumption and carbon reductions it is crucial to act in new, but also in existing buildings, which constitute the majority of the building stock. In existing buildings, the significant improvement of their efficiency requires important investments. Therefore, costs are a major concern in the decision making process and the analysis of the cost effectiveness of the interventions is an important path in the guidance for the selection of the different renovation scenarios. The Portuguese thermal legislation considers the simple payback method for the calculations of the time for the return of the investment. However, this method does not take into consideration inflation, cash flows and cost of capital, as well as the future costs of energy and the building elements lifetime as it happens in a life cycle cost analysis. In order to understand the impact of the economic analysis method used in the choice of the renovation measures, a case study has been analysed using simple payback calculations and life cycle costs analysis. Overall results show that less far-reaching renovation measures are indicated when using the simple payback calculations which may be leading to solutions less cost-effective in a long run perspective.

With the objective of fostering the energy efficiency of the building sector as well as of the integration of renewable energy sources, the adoption of near Zero Energy Buildings ( nZEB) concepts (buildings that have a very high energy performance) in new and in existing buildings, is currently being promoted by the SouthZEB project. This Project, initiated in March 2014, is developing, in 30 months, certified training modules targeted towards engineers, architects, municipality technicians and decision makers in Southern European countries, including Portugal. Training modules definition considers the experience and know-how of the front-runner countries (Austria, UK and Northern Italy) participating in the project, but are also based on the counselling of representatives of the main nZEB stakeholders in each of the Southern European countries partnering the SouthZEB project (Portugal, Italy, Greece and Cyprus), the so-called SouthZEB National Support Groups. This paper, first, elaborates on the nZEB concept and its adoption evolution in Europe. Secondly, it focuses on the need for professional training, which has been a barrier encountered in nZEB progress in Southern European countries. Finally, the paper presents the certified training development methodology followed by the SouthZEB project, with a particular focus in the Portuguese experience., SouthZEB Project is co-funded by the Intelligent Energy Europe Programme of the European Union IEE/13/393/SI2.675576 and the sole responsibility for the content of this paper lies within the authors. It does not necessarily reflect the opinion of the European Union. Neither the EASME nor the European Commission are responsible for any use that may be made of the information contained herein . .

Improving energy efficiency in existing buildings is a great challenge. These buildings have their own limitations related with their design, location and function. To study the possibilities of cost-effectively improve the thermal performance of these buildings and increase the chances of reaching the nearly zero energy (nZEB) target, one building of Rainha Dona Leonor neighbourhood has been analysed. The purpose of the study was to analyse the robustness of the cost optimal methodology when renovating towards nZEB targets. With this work it was possible to understand that the most cost effective package of renovation measures to achieve cost optimal levels and to achieve the nZEB target are very similar and these results do not suffer major changes when variations on the energy prices, discount rates or photovoltaic (PV) costs are considered. However, these changes make the use of PV more cost-effective and nZEB levels become, sometimes, also cost optimal levels.

The European roadmap towards a competitive low carbon economy in 2050 raised the awareness about buildings energy performance due to their potential for cost-effective energy consumption and carbon emissions reductions. For the evaluation of the levels of energy performance of buildings, the European Commission presented the Cost Optimal Methodology allowing comparing different energy performance levels of buildings and buildings components and identifying those with the lowest associated cost considering the building life cycle. This study, using four reference buildings from the Portuguese building stock, where some scenarios for the improvement of their energy performance were analysed with the purpose of identifying the cost-optimal levels, compares the economic performance of different measures. Results provide guidance for the assertive combination of elements for new buildings and for building packages of renovation of measures, as well as for the choice of individual measures in partial renovation scenarios, which, beyond common, are usually performed without the control of the national energy certification system.

Promoting the improvement of the overall energy performance of buildings is a relevant part of the European climate action and the Roadmap for moving towards a competitive low carbon economy in 2050, with an expectation of reducing greenhouse gas (GHG) emissions by around 90% when compared to 1990 values, in the area of the built environment. The recast of the European Energy Performance of Buildings Directive (EPBD) introduced the goal of nearly zero-energy buildings (nZEB) for all new buildings from January 1st, 2021 and plans should be drawn to stimulate the transformation of existing buildings that are refurbished into the same concept. EPBD also requires that all European Member States must ensure that the minimum energy performance requirements for buildings are set to achieve optimal levels, i.e. the energy performance levels that lead to the minimum cost during the life cycle. Therefore, Cost Optimality and nZEB are two fundamental concepts within the current European Union policy related to the energy performance of buildings and consequently related to climate change mitigation and non-renewable resources consumption, with Cost Optimality mainly focused on costs and nZEB focused on low energy consumption levels and on site renewables harvesting. In this context, this paper, using two characteristic buildings of the Portuguese residential building stock, aims at presenting the results that emerged from the analysis and identification of the most cost-effective packages of renovation measures needed to adapt existing buildings to zero energy balance and comparing them with those resulting from the calculation of cost-optimal levels.The investigation of the trade-offs between a renovation towards zero energy balance and a cost optimal renovation without energy use restrictions is relevant to provide clues to the development of national plans for increasing the number of nZEB and to provide appropriate financing and other instruments to catalyze this transformation.

Due to buildings high energy consumption their refurbishment is essential to achieve the targets defined by the EPBD-recast regarding energy efficiency and reduction of carbon emissions. Besides the energy efficiency, the sustainability and the Indoor Environmental Quality (IEQ) of Buildings must also be considered when planning a refurbishment project. Thus, to propose an effective building refurbishment it is necessary to select the adequate construction solutions taking into account their impact on the energy performance, thermal and acoustic comfort, indoor air quality and environmental impact of the building. In this work a multi-criteria decision analysis method is applied to balance all these aspects in a refurbishment project, in order to assist the design team on the selection of the construction solutions. Throughout the multi-criteria analysis performed, it was possible to verify that the rehabilitation solutions with lower embodied energy were the best refurbishment options.

Building rehabilitation is essential to achieve the targets defined by the EPBD recast regarding energy efficiency, reduction of carbon emissions and use of on-site renewable energy sources. Besides the energy efficiency the Indoor Environmental Quality of Buildings (IEQ) and environmental impact must also be considered when planning a refurbishment project. Thus to propose an effective building rehabilitation is necessary select the adequate construction solutions taking into account their impact on the energy performance, thermal and acoustic comfort, indoor air quality and environmental impact of the building. In this work a multi-criteria decision analysis method, ELECTRE III, is applied to balance all these aspect, during the design phase of a refurbishment project, in order to assist the design team on the selection of construction solutions. Throughout the multi-criteria analysis performed, it was possible to verify that the rehabilitation solutions with lower embodied energy were the best refurbishment options.

The climate and energy package is a set of binding legislations which aims to ensure the European Union meets its ambitious climate and energy targets for 2020. These targets, known as the "20-20-20" targets, have set three key objectives: a 20% reduction in the EU greenhouse gas emissions, a 20% rise in the share of EU energy consumption produced from renewable resources and a 20% improvement in the energy efficiency. More renewable energies will enable the EU to lower greenhouse emissions and make it less dependent on imported energy. Boosting the industry of renewables will encourage technological innovation and employment in Europe. On this topic, photovoltaic façades are known to be a solution that allows both energy efficiency and environmental performance of buildings. This paper reports on a study of façade systems that have incorporated photovoltaic panels, considering computational simulations for Portugal. The main objective is to analyze the characteristics and parameters that define more efficient systems based on computer simulations carried out by Solterm 5.0. The results show the high potential of the use of the proposed technology in Portugal, especially in the Southern region, because of its latitude. Regarding energy efficiency and environmental performance, inclined polycrystalline silicon solar panels achieved the best results and the most efficient panel was Kyocera KC167G-2, followed by BP 3160. The comparison between simulation results and results provided in the literature shows that the use of computer programs is viable to the analysis of the energy efficiency of photovoltaic systems in façades.

High performance glass and Trombe walls in the façade was studied in this research. The paper reports results of an ongoing investigation on a new façade system concept, designed as: “Façade Modules for Eco-Ef! cient Refurbishment of Buildings”, especially on energy ef! - ciency of Trombe wall and glazing modules arrangement. Computational simulation was carried out by using the software DesignBuilder. Two double glazing types and Trombe walls were considered for three different climates in Portugal and four solar orientations. Results obtained for heating energy needs were compared to all façade con! gurations. The use of Trombe wall and the double self-cleaning glass in the façade point towards a signi! cant decrease of heating energy needs. The great majority of the façades combinations presented energy needs lower than the maximum allowed by the Portuguese regulation (RCCTE)., Esta investigación aborda el estudio de fachadas con cristales de altas prestaciones y muros Trombe. El artículo presenta los resultados de la investigación en curso sobre un nuevo concepto en sistemas de fachada, denominado "Módulos de fachada para el acondicionamiento ecoe ! ciente de edi! cios", especialmente enfocado a la e! ciencia energética de muros Trombe y módulos con doble acristalamiento. Haciendo uso del software DesignBuilder se realizaron simulaciones de una estancia, analizando distintos conjuntos de fachadas modulares. Para la realización de las simulaciones se consideraron dos tipos de módulos de doble acristalamiento, dos con! guraciones de muros Trombe, tres climas diferentes en Portugal y cuatro orientaciones solares. Se compararon los requerimientos de calefacción de cada una de las con! guraciones, observándose que tanto los muros Trombe como los módulos de doble acristalamiento presentaron disminuciones signi! cativas en cuanto a requerimientos de calefacción. De las con! guraciones analizadas, la mayoría presentó demandas energéticas de calefacción menores a lo especi! cado en la normativa portuguesa (RCCTE).

Building rehabilitation is essential to achieve the targets defined by the EPBD-recast regarding energy efficiency, reduction of carbon emissions and use of on-site renewable energy sources. Besides the energy efficiency the Indoor Environmental Quality of Buildings (IEQ) must also be considered when planning a rehabilitation project. Thus to propose an effective building rehabilitation is necessary select the adequate construction solutions taking into account their impact on the energy performance, thermal and acoustic comfort and indoor air quality of the building. In this work a multi-criteria decision analysis method, ELECTRE III, is applied to balance all these aspect, during the design phase of a refurbishment project, in order to assist the design team on the selection of construction solutions.

Building rehabilitation is essential to achieve the targets defined by the EPBD-recast regarding energy efficiency. Besides the energy efficiency the Indoor Environmental Quality (IEQ) and environmental impact must also be considered when planning a rehabilitation project. Thus to propose an effective building rehabilitation it is necessary to select the adequate construction solutions taking into account their impact on the energy performance, thermal and acoustic comfort and environmental impact of the building. In this work, ELECTRE III method is applied to assist the design team on the selection of construction solutions. A simple case study is presented to show this approach in what concerns the selection of construction solutions (thickness and placement of insulation materials and construction solution options) of a rehabilitation project.

In average, man spends about 90% of the time inside enclosed spaces, in both residential and office buildings, exposed to consistently higher concentrations of air pollutants than outdoors, which has led to the increased rate of allergies and asthma incidences. In the last decade, public and governmental awareness on indoor air quality (IAQ) has been growing. Portugal implemented the National Building Energy and Indoor Air Quality Certification System in 2006 which imposes periodic IAQ audits for office buildings. However, in residential buildings, the only normative imposition related to IAQ is the obligation of a minimum air change rate of 0.6 h-1. The number of potential pollutants inside residential buildings is significant, and even low concentration levels can cause health problems if combined effects are considered. Additionally, the inhabitants’ behaviour can have a significant impact on IAQ. Therefore, the assessment of IQA is very important. This paper presents the application of the IAQ audit methodology, defined by the Portuguese legislation for office buildings, to residential buildings. The concentration of suspended particles, carbon dioxide, carbon monoxide, ozone, formaldehyde and total volatile organic compounds were measured as well as the air change rate. A standard questionnaire was delivered to the inhabitants to also obtain a subjective assessment of the IAQ. The goal of this study was to verify the IAQ conditions inside the Portuguese residential buildings and to establish a comprehensive IAQ audit approach for residential buildings. The results gathered will also be used to identify the main problems of Portuguese residential building stock and to develop guidelines to improve IAQ in residential buildings.

The energy efficiency of buildings is nowadays one of the main concerns of the construction market. But, Indoor Environmental Quality of Buildings (IEQ) should not be disregarded. To achieve an adequate quality of buildings it is necessary to consider a set of aspects that are interconnected and influence each other, not always in a favourable way. The selection of the most suitable construction solution and materials for the building elements must consider its contribution for the IEQ (thermal and acoustic comfort, daylight conditions and the indoor air quality) inside the buildings, its energy efficiency and its environmental impact (considering the embodied energy, for example), but also the weight of the solution and its effect on the structural project of the building. The solutions adopted in buildings, usually, only optimize no more than one of the necessary comfort requirements. In many cases, the best solutions to accomplish different comfort requirements are not compatible, especially in what concerns natural ventilation and lighting strategies and the acoustic and thermal performance. So, it is necessary to have an integrated approach to ensure the best overall behaviour taking into account all of the, sometimes incompatible, comfort and energy efficiency requirements. In this work the use of a multi-criteria analysis, to balance all these aspects on the design phase, in order to assist the designer in the selection of construction solutions and materials will be presented. The selection of the most adequate construction solutions will increase the buildings IEQ, energy performance and also its environmental impact.

Energy performance and building energy efficiency can be achieved by high performance façade systems. Building façades constitute a privileged component to propose solutions, once they have a major influence in the energy consumption in the building and in occupants comfort. Recently, façade systems are increasingly integrating not only sophisticated active systems devices, but also passive solutions. High performance glass and Trombe wall are the façade system improvement in this research work. This paper reports the results of an ongoing investigation on a new façade system concept, designed as: "Façade Modules for Eco-Efficient Refurbishment of Buildings", especially on thermal performance of Trombe wall and glazing modules arrangement. Computational simulation was done with the Design Builder software having as object a room (25 m²) with different arrangements of façade modules. Two different double glazing types (composed by green solar control glass and low-e glass; self-cleaning glass and float clear glass) were considered for four different climates in Portugal (Bragança, Coimbra, Évora and Faro). The use of a façade with one and two combined modules of Trombe walls was studied for four solar orientations (north, south, east and west). Results obtained for heating energy needs were compared to all façade configurations. They indicated a decrease of heating energy needs by the use of one or two Trombe wall and double self-cleaning glass in the façade. These solutions presented a better performance in comparison with others types studied, decreasing heating energy necessities. The great majority of the façades combinations presented heating energy needs lower than the maximum allowed by the Portuguese regulation (RCCTE).

To achieve an adequate quality of buildings it is necessary to consider a set of aspects that are interconnected and influence each other, not always in a favourable way. The selection of the most suitable construction solution and materials for the building elements must consider its contribution for the thermal and acoustic comfort, the daylight conditions and the indoor air quality inside the buildings, its energy efficiency, but also the weight of the solution and its effect on the structural project of the building. The solutions adopted in buildings, usually, only optimize no more than one of the necessary comfort requirements. In many cases, the best solutions to accomplish different comfort requirements are not compatible, especially in what concerns natural ventilation and lighting strategies and the acoustic and thermal performance. Thus, it is necessary to provide designers with methodologies with an integrated approach, that allow them to take into account, since an early stage of the design phase, all of the, sometimes incompatible, comfort requirements, to ensure the best overall behaviour of the buildings. In this work the use of a multi-criteria analysis, to balance all these aspects on the design phase, in order to assist the designer in the selection of construction solutions and materials will be presented. The criteria selected are related to the most important characteristics of the indoor environmental quality, the thermal and acoustic comfort, it is possible to define them in an early stage of the design phase, in a non subjective way, are under the designer scope and are the issues that are also the most valued by the users of the buildings.

To achieve an adequate quality of buildings it is necessary to consider a set of aspects that are interconnected and influence each other, not always in a favourable way. The selection of the most suitable construction solution for the building elements must consider its contribution for the thermal comfort, the Indoor Air Quality, the daylight conditions inside the buildings, its energy efficiency and the acoustic behaviour. In this work the use of a multi-criteria decision analysis method, to balance all these aspects on the design phase, in order to assist the designer in the selection of design alternatives, construction solutions and materials regarding the different aspects that affect the Indoor Environmental Quality and the energy performance of the buildings is presented. The selection of the most suitable design alternative will increase the buildings thermal behaviour and also its energy performance. The proposed multi-criteria method allows buildings to be rated according to their energy use and comfort conditions, or by using a set of parameters involving environmental factors. Throughout the multi-criteria analysis performed, it was possible to verify that the overall comfort exigencies are not restrictive, because there are a large number of constructive solutions that, when adequately used, will assure all the needs, being only necessary to integrate the exigencies of all the different requirements.

To achieve an adequate quality of buildings it is necessary to consider a set of aspects that are interconnected and influence each other, not always in a favourable way. The selection of the most suitable construction solution for the building elements must consider its contribution to the thermal and acoustic comfort inside the buildings, the daylight conditions, its energy efficiency and sustainability, and also the weight of the solution and its effect on the structural project of the building. In this work, the use of a multi-criteria analysis, to balance all these aspects on the design phase, in order to assist the designer in the selection of construction solutions and materials, will be presented. The selection of the most adequate construction solutions will increase the buildings thermal and acoustic behaviour and also its energy performance and sustainability., (undefined)

Sustainability in the Building sector is nowadays a major concern. Taking in consideration that in the EU buildings account for about 40% of the total energy consumption (35% in Portugal), the EU Directive 2002/91/EU on Energy Efficiency in Buildings (EPBD), recently reinforced with the "EPBD-recast", imposes an increasingly stronger control of the energy consumption in this sector while maintaining, or even improving, their indoor environmental quality (IEQ). But, as buildings are complex systems, where all aspects are interconnected and influence each other, not always in a favourable way, an integrated and comprehensive approach to the buildings design, that enhance indoor health and comfort besides the energy savings, should be followed. In this work it is presented a multi-criteria analysis, suitable for the design phase that balances all these aspects, with the potential of becoming a valuable tool to assist the designer in the most appropriate selection of design alternatives, construction solutions and materials.

Dissertação de mestrado em Sustainable Built Environment, The building stock is responsible for 40% of the energy consumption and 36% of greenhouse gas emissions in Europe. The European Energy Performance of Building Directive (EPBD) established instructions to promote building energy performance to mitigate this problem. Since its first publication in 2002, energy efficiency has been increasingly promoted. In particular, the 2010 recast introduced the nearly zero energy building concept (nZEB), a cost-effective building with low energy demand while having most of its energy demand supplied by renewable energy sources (RES). The procedure for developing a nZEB building includes a cost-optimal assessment of the elements and systems of the buildings, which is the cost-effective comparison between reference building solutions and the proposed building solutions. The cost-optimal assessment has fomented researches aiming to find more cost-effective and energy-efficient building solutions. Furthermore, building methods such as modular and offsite construction have been studied for their possible contribution to increasing cost-effectiveness, energy efficiency, and sustainability. In this context, this study focused on developing a modular solution for the external walls to be used in prefabricated housing. The methodology developed in this dissertation includes developing a catalogue for existing modular solutions, designing the studied building, simulating, and optimizing results, and the cost-optimal analysis of the achieved results for a single-family housing. The data was gathered through a Building Energy Model (BEM) analysis in the software Design-Builder running the Energy-Plus engine simulation. The cost-optimal analysis was performed by comparing different combinations of optimised external envelope options and building solutions. The study analysis shows that an external building envelope can be achieved with lower initial and global costs and lower energy needs than traditional construction. This study shows that the cost-optimal solution for the designed building is a light steel frame panel with an MDF wood façade panel of 22mm, an internal OSBIII panel of 15mm and 90mm Mineral wool insulation material., O ambiente construído é responsável por 40% da energia consumida e 36% das emissões de gases com efeito de estufa na Europa. A Diretiva para o Desempenho Energéticos dos Edifícios (EPBD) estabeleceu instruções para promover o desempenho energético e térmico de edifícios para mitigar este problema. Desde a primeira publicação em 2002, a eficiência energética vem sendo fomentada. Em particular, a reformulação em 2010 introduziu o conceito de edifícios com necessidades quase nulas de energia (nZEB), um edifício custoeficaz com baixas necessidades energética que tem a maior parte dessas necessidades sendo fornecida por energias renováveis. O procedimento de desenvolvimento de um nZEB inclui a análise de custo óptimo dos sistemas e elementos do edifício, comparando entre a solução de referência e as soluções propostas. A análise de custo óptimo fomenta pesquisas focadas em achar mais soluções de melhor custo eficácia e de eficiência energética. Ademais, métodos de construção como edifícios modulares e pré-fabricados são estudados por possíveis contribuições para aumento de custo eficácia, eficiência energética e sustentabilidade. Neste contexto, este estudo focou-se no desenvolvimento de uma solução modular para paredes externas para ser utilizada em habitações pré-fabricadas. A metodologia desenvolvida nesta dissertação inclui o desenvolvimento de um catálogo para soluções modulares existentes, a criação do projeto de estudo, simulação e optimização, e análise de custo ótimo para uma habitação unifamiliar. Os dados foram recolhidos por meio de uma análise de um modelo energético de construção (BEM) pelo software Design-Builder utilizando o motor de simulação do Energy-Plus. A análise de custo óptimo foi feita comparando diferentes combinações de envolvente externa optimizada. A análise de estudo mostrou que é possível alcançar uma envolvente com custo inicial, custo total e necessidades energéticas menores quando comparada com a construção tradicional que se pratica no contexto português. Este estudo mostra que a solução de custo óptimo para o edifício projetado é um painel com estrutura em construção metálica leve (LSF), com um placa de madeira MDF de 22 mm na fachada, uma placa interna de painel estrutural com fibras orientadas de madeira (OSB) III de 15 mm, e o isolamento em lã mineral de 90 mm.

Dissertação de mestrado integrado em Engenharia Civil, Face ao elevado consumo de energia e emissão de gases com efeito de estufa do parque edificado, existe, como consequência, a necessidade de fomentar políticas que providenciem uma melhoria do desempenho energético do mesmo. Nesta perspetiva, a reabilitação de edifícios existentes e o aumento da eficiência energética dos mesmos é de uma importância fundamental para o alcance dos objetivos definidos em termos de desenvolvimento sustentável. Em 2010, com a reformulação da EPBD, a Comissão Europeia tomou uma posição bastante exigente neste sentido, estabelecendo o conceito de edifícios de necessidades quase nulas de energia (nZEB), que se caracterizam como edifícios com elevado desempenho energético e baixas necessidades energéticas, suportadas por fontes de energia renovável, produzida preferencialmente no local. Em termos de reabilitação energética de edifícios existentes, existem evidências de que uma intervenção ao nível de um grupo de edifícios pode trazer vantagens significativas do ponto de vista de combinação entre medidas de eficiência energética e fornecimento de energia renovável, para além da possibilidade de obtenção de economias de escala. Assim, o objetivo do desenvolvimento desta dissertação é a definição de uma metodologia para a avaliação do efeito de escala na rentabilidade de intervenções de reabilitação, com vista ao objetivo nZEB. Como objetivo adicional, a investigação pretende ainda a determinação de pacotes de soluções de reabilitação com o nível ótimo de rentabilidade à escala de bairro, com o intuito de aproveitar as potenciais sinergias entre as medidas a adotar nos diferentes cenários de reabilitação. Com o propósito de pôr em prática a metodologia desenvolvida, foi selecionado um grupo de edifícios num contexto de habitação social como caso de estudo – O Bairro de Santa Tecla em Braga. O estudo realizou-se através da utilização de uma tipologia representativa (fração com maior representação no bairro) e posterior avaliação do seu desempenho energético e financeiro com o intuito de apoiar a transição para a escala de bairro. Os resultados, decorrentes da aplicação da metodologia, sugerem que uma intervenção integrada, que contempla medidas de melhoria na envolvente, sistemas de climatização e fontes de energia renovável, é extremamente vantajosa e pode atingir valores interessantes de rentabilidade, em comparação com a intervenção de referência. Para uma perspetiva privada, com vista ao apoio de escolha de soluções, nos cálculos efetuados para a tipologia representativa desenvolvida para este estudo, a intervenção que contempla uma solução ETICS com EPS de 60 mm, vão envidraçado duplo com caixilharia de PVC e o conjunto de Sistemas S3 (bomba de calor) é a solução de custo ótimo. Quando se considera uma intervenção no grupo de edifícios, os cálculos sugerem que a solução de custo ótimo é a mesma solução de envolvente e envidraçados com o sistema S3, verificando-se que a intervenção ao nível do grupo de edifícios permitiu uma redução de custos globais de cerca de 46% devido à alteração de sistemas técnicos e consequente diminuição nas quantidades dos mesmos, e ainda às economias de escala conseguidas pela compra de elevadas quantidades de materiais utilizados em soluções de paredes exteriores e de vãos envidraçados., In view of the high energy consumption and greenhouse gas emissions of the existing buildings stock, there is, as consequence, the need to promote policies that provide an improvement of their energy performance. In this perspective, the retrofitting of existing buildings and the increase of their energy efficiency are of fundamental importance for achieving the objectives defined in terms of sustainable development. In 2010, with the EPBD recast, the European Commission took a very demanding position in this regard, establishing the concept of nearly zero-energy buildings (nZEB), which are characterized as buildings with high energy performance and low energy needs, sustained by renewable energy sources, preferably produced on site or neaby. In terms of energy retrofitting of existing buildings, there is evidence that an intervention at the group of buildings level can bring significant advantages from the point of view of a combination between energy efficiency measures and renewable energy supply, in addition to the possibility of obtaining economies of scale. Thus, the objective of the development of this dissertation is the definition of a methodology for the assessment of the scale effect on the retrofitting interventions cost-effectiveness, towards the nZEB objective. As an additional objective, the research also aims to determine the cost-optimal packages of renovation solutions at the neighbourhood level, in order to take advantage of the potential synergies between the measures to be adopted in the different retrofitting scenarios. With regard to the development of the methodology, a group of buildings was selected in the context of a social housing as a case study - The Neighbourhood of Santa Tecla in Braga. The study was carried out through the use of a representative typology (building unit with most representation in the neighbourhood) and subsequent evaluation of its energy and financial performance in order to support the transition to the group of buildings level. The results, arising from the application of the methodology, suggest that an integrated intervention that includes retrofitting measures in the envelope, air conditioning systems and renewable energy sources is extremely advantageous and cost-effective when compared to the reference intervention. For a private perspective, in order to support the selection of solutions, in the calculations made for the representative typology developed for this study, the intervention that contemplates an ETICS solution with EPS of 60 mm, double glazed windows with PVC frames and the set of S3 systems (heat pump) is the cost-optimal solution. When considering an intervention in the group of buildings, the calculations suggest that the cost-optimal solution is the same envelope and window solution with the S3 system, verifying that the intervention at the group of buildings level allowed a reduction of global costs of around 46% due to the alteration of technical systems and consequent decrease in their quantities, and also to the economies of scale provided by the purchase of high quantity of materials used in solutions of exterior walls and windows.

Dissertação de mestrado integrado em Engenharia Civil, Em 2011, o número de alojamentos em Portugal superou em 45% o número de famílias sendo que cerca de 32% dos alojamentos existentes eram residências secundárias ou estavam desocupados. Além disso, os edifícios são responsáveis por uma percentagem muito significativa de emissões de gases que contribuem para o efeito de estufa bem como de energia consumida, devido às elevadas necessidades energéticas dos mesmos. Assim, torna-se imperativo proceder à reabilitação do parque habitacional em detrimento da construção nova. Esta mudança de paradigma contribuirá para um desenvolvimento mais sustentável do setor da construção, para uma valorização do nosso património, bem como para uma melhoria do conforto térmico dos ocupantes dos edifícios. Com este estudo pretende-se identificar, avaliar e analisar materiais e soluções construtivas, aplicáveis em situações de reabilitação que visem melhorar o conforto térmico e desempenho energético dos edifícios, aliado a um custo de ciclo de vida reduzido. Para tal, realizou-se uma pesquisa de mercado de modo a identificar as soluções construtivas e respetivas características técnicas para posteriormente serem simuladas no software de simulação numérica EnergyPlus, bem como avaliadas segundo uma análise multicritério baseada na metodologia MARS-SC. Deste modo, foi possível avaliar o desempenho térmico, energético e económico de cada solução construtiva individualmente, mas também conjugando algumas soluções simultaneamente segundo propostas de cenários de reabilitação. Espera-se assim que este trabalho contribua de forma positiva e significativa, não só em obras de reabilitação, mas também em obras novas para a seleção de soluções construtivas por parte dos projetistas que pretendam proporcionar, em simultâneo, uma otimização do desempenho energético, térmico e económico do edifício, visando também uma reabilitação mais sustentável., In 2011, the number of accommodations in Portugal overcame in 45% the number of families, being that about 32% of the existing accommodations were secondary residences or they were unoccupied. Moreover, the buildings are responsible for a very significant percentage of pollutant emissions that contribute for the greenhouse effect as well as the energy consumed, due to their energy needs. Thus, it is imperative to proceed with the rehabilitation of the existing stock in detriment of the new construction. This paradigm shift will contribute to a more sustainable development of the construction sector, a valuation of our heritage, as well as an improvement in the thermal comfort of the occupants of the buildings. This study intends to identify, evaluate and analyze constructive materials and solutions applicable in rehabilitation situations that aim to improve thermal comfort and energy performance of buildings, together with a reduced life cycle cost. For that, a market research was carried out in order to identify the construction solutions and their technical characteristics to be simulated later in the EnergyPlus numerical simulation software, as well as evaluated according to a multicriteria analysis based on the MARS-SC methodology. In this way, it was possible to evaluate the thermal, energy and economic performance of each construction solution individually, but also to conjugate some solutions simultaneously according to rehabilitation scenarios proposals. It is hoped that this work will contribute positively and significantly, not only to rehabilitation works but also to new works, for the selection of constructive solutions on the part of the designers who wish to simultaneously provide an optimization of the energy, thermal performance and economic development of the building, aiming also for a more sustainable rehabilitation.

Dissertação de mestrado integrado em Engenharia Civil, O consumo energético e as emissões de gases com efeito de estufa têm assumido ao longo do tempo um grande destaque. O sector dos edifícios distingue-se como um dos maiores consumidores de energia, consequentemente representa um forte contributo para as emissões de gases com efeito de estufa. Deste modo, e sabendo que existe uma grande necessidade de reabilitação do parque habitacional, é possível afirmar que a reabilitação tem um papel determinante no sentido da eficiência energética e uma forma de tornar a economia, numa economia segura e sustentável. A presente dissertação tem como principal objetivo a otimização das soluções de reabilitação de um edifício multifamiliar, localizado em Vila Nova de Gaia. As diferentes medidas de reabilitação implementadas visam a obtenção de um edifício eficiente a custos reduzidos. Para tal, efetuou-se uma abordagem de otimização da relação custo-benefício, ao mesmo tempo que foi ponderada a viabilidade de três cenários de reabilitação diferentes: redução em 80% das necessidades energéticas face à situação inicial, nível nZEB (edifício com necessidades quase nulas de energia) e nível ZEB (edifício com necessidades nulas de energia). Numa primeira fase, foi avaliado o desempenho térmico do edifício na situação atual de acordo com a metodologia da regulamentação térmica em vigor (Regulamento de Desempenho Energético dos Edifícios de Habitação - REH). Definiram-se diferentes soluções de reabilitação da envolvente, bem como diferentes sistemas técnicos (sistemas de climatização, sistemas solares térmicos e fotovoltaicos), e comparou-se a redução das necessidades energéticas conseguidas com a implementação das diferentes soluções de reabilitação estudadas. Por fim, avaliou-se o potencial do contributo de fontes de energia renovável associado à integração de sistemas solares térmicos e fotovoltaicos. A análise do conjunto de medidas de reabilitação definidas permitiu obter um conjunto de soluções de custo ótimo. Por outro lado, conseguiu-se atingir o nível ZEB e, embora o nZEB ainda não se encontre completamente definido, é possível alcança-lo, uma vez que diversas soluções estudadas potenciam reduções dos consumos energéticos na ordem dos 90% e 95% face à situação inicial., Energy consumption and greenhouse gas emissions have become more significant over time. The building sector is one of the largest energy consumers and consequently as a major contributor to greenhouse gas emissions. Thus, knowingly that there is a great need for renovation of the housing stock, it is possible to affirm that renovation plays a decisive role in improvement of the energy efficiency and a way of developing a safe and sustainable economy. The present work main objective was the optimization of the renovation solutions of a multi-family building, located in Vila Nova de Gaia (Portugal). The different renovation measures implemented aim to obtain an efficient building at a reduced cost. A cost optimal approach was carried out while the feasibility of three different scenarios was considered: 80% energy needs reduction compared to the initial situation, reaching the nZEB (nearly Zero Energy Building) and ZEB (Zero Energy Building) levels. Initially, the thermal performance of the building current situation was evaluated using the methodology defined in the Portuguese thermal regulation. Different renovation solutions of the envelope were defined and their impact in the building’s energy efficiency was analyzed. Different technical systems were also defined based on their efficiencies and availability in the market. Finally, the potential contribute of renewable energy sources (solar thermal and photovoltaic systems) was also evaluated. The analysis of the wide range of renovation measures defined for the building allowed to obtain a set of optimum cost solutions. It was possible to reach the ZEB level and, although the nZEB is not yet quantitatively defined in Portugal, it is possible to reach this efficiency level since several solutions potentiate reductions in the energy needs around 90% and 95% compared to the initial situation.

Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Construções), O setor dos edifícios é central para a política de eficiência energética da UE, sendo responsável por cerca de 40% do uso total de energia e de 36% das emissões de CO2 em toda a Europa1 . Melhorar o desempenho energético do stock de edifícios europeus é, portanto, crucial não só para alcançar as metas europeias 20/20/202 mas também para o cumprimento de metas a longo prazo, nomeadamente a estratégia climática europeia de economia de baixo carbono 2050. Neste sentido, apesar do reconhecimento do enorme potencial das medidas de reabilitação energética de edifícios, tem sido difícil a sua eficaz exploração em virtude de uma visão demasiado redutora por onde decisores/promotores/proprietários se guiam. Consideram (maioritariamente) como contrapartidas inerentes à aposta em medidas de renovação de eficiência energética de edifícios, a poupança de consumo de energia e dos custos com a energia (efeitos diretos), negligenciando todos os outros benefícios (positivos ou negativos) também eles bastante relevantes denominados de co-benefícios como a melhoria geral da qualidade da construção, melhoria do bem-estar dos ocupantes, etc. Isto conduz a que o valor integral da melhoria do edifício reabilitado seja subestimado a vários níveis, nomeadamente a nível financeiro (Ürge-Vorsatz, Novikova, & Sharmina, 2009), social e ambiental (IEA, 2012), com repercussões ao nível dos ocupantes/proprietários como ao nível da sociedade. Neste sentido, a presente dissertação foi desenvolvida com o objetivo de identificar e avaliar os co-benefícios decorrentes de uma reabilitação energética através de inquéritos aos moradores de um caso de estudo (Vila d’ Este). Também era objetivo medir um conjunto de parâmetros ambientais (humidade relativa do ar, temperatura ambiente e acústica) que pudessem suportar essa avaliação subjetiva (inquéritos) dos moradores. Os resultados obtidos (inquéritos e medições) permitiram constatar que de facto os moradores reconhecem os efeitos benéficos do conjunto de medidas de reabilitação energética implementadas muito além dos benefícios diretos o que traduz a importância de promover a integração dos co-beneficios da reabilitação energética no processo de decisão., The Buildings sector is central to the energy efficiency strategy of the EU. The sector is responsible for 40% of the energy consumption and 36% of the CO2 emissions in all of Europe. Improving the energetic performance of the european building stock is thus crucial to achieve the 20/20/20 goal, but also to fulfil the long term goals of the european climate strategy for a low carbon economy by 2050. Despite the almost unanimous acknowledgment of the enormous potential of building renovation measures to improve energy efficiency, their implementation has been slow due to the short sighted vision of decision makers and owner alike. Those consider (mainly) as counterparts, inherent to the investment of building renovation measures to improve energy efficiency, the savings from a lower energy consumption and energy costs (direct effects), neglecting all other relevant benefits also called co-benefits as the general improvement of building quality, improve the well-being of the occupants, etc.The full benefits of building rehabilitation are underestimated, namely on the financial (Ürge-Vorsatz, Novikova, & Sharmina, 2009), social and environmental level (IEA, 2012). This underestimation has repercussion to building residents and the wide economic system. Thus, the present dissertation was developed with the goal of evaluating the co-benefits of an energy rehabilitation through surveys as well as with environmental parameters measurements (relative humidity, ambient temperature and acoustic) that support the analysis of the survey results, using a case study in which a set of buildings has undergone energy rehabilitation works (Vila d'Este). The results obtained by the subjective evaluation of the residents (surveys) as well as the measurement of environmental parameters showed that it in fact residents of the analyzed rehabilitated buildings recognize the beneficial effects of the set of energy rehabilitation measures implemented beyond the direct benefits. This reflects the importance of promoting the integration of co-benefits of energy rehabilitation in the decision process.

Dissertação de mestrado integrado em Engenharia Civil, Com o acelerado crescimento populacional do passado século, a indústria da construção teve necessidade de se reajustar para acompanhar este crescimento. Consequentemente, isto trouxe um acréscimo do consumo de recursos naturais e que levou à deterioração dos ecossistemas. Este aumento de consumo também levou à produção excessiva de resíduos e naturalmente a uma alteração das condições do planeta. A crescente utilização de combustíveis fósseis também conduziu a uma dependência externa de energia por parte de muitos países da União Europeia. A indústria da construção precisa de uma mudança profunda, pois é necessário reduzir o consumo de recursos naturais e também a dependência energética. Esta transformação surge aquando do conceito de renovação energética, onde é possível utilizar o edificado existente, tornando-o menos dependente de combustíveis fósseis. Esta solução não só produz menos resíduos, mas também tenta explorar a redução dos gases de efeito de estufa na atmosfera. A par da reabilitação energética é preciso pensar na rentabilidade económica de cada uma das soluções aplicadas, para que cada medida possa dar um sentido de alcance a conceitos como nZEB (nearly Zero Energy Building – Edifício com necessidades quase nulas de energia) e ZEB (Zero Energy Building – Edifício com necessidades nulas de energia). Na presente dissertação são estudadas medidas comuns de reabilitação energética do edificado português, e também a comparação destas com as medidas propostas pelo projeto MORE-CONNECT para um edifício piloto em Portugal. O projeto prevê a aplicação de painéis pré-fabricados para a renovação da envolvente do edifício. Estes elementos não só vão permitir melhorar o desempenho térmico do edifício, como lhe estão associados custos reduzidos e um tempo de aplicação curto. A meta a atingir com esta dissertação é não só avaliar o impacto, em termos térmicos e económicos, da aplicação dos painéis desenvolvidos no âmbito do projeto MORECONNECT, mas também avaliar se a sua aplicação conduz a um edificado mais perto das metas da União Europeia para 2020., With the population growth observed on the last century, the construction industry needed major changes to keep up with this growth. This, consequently, brought an increase in the consumption of natural resources which led to a deterioration of the ecosystems. This increased consumption also led to excessive production of waste, and thus, to changes in the planet. The increasing use of fossil fuels also led to a dependence on external energy by many countries of the European Union. The construction industry needed a deep change, as it is necessary to reduce the consumption of natural resources and energy dependence. Energy rehabilitation is the promising concept that brings a new look into reducing energy consumption of existing buildings. With this concept, it is possible to make improvements on existing buildings, thus making them less dependent on fossil fuels. This solution not only produces less waste, but also tries to explore the reduction of greenhouse gases in the atmosphere. Along with energy rehabilitation, it is essential to consider the economic viability that such rehabilitation solutions can bring, so that these solutions can reach nZEB (nearly Zero Energy Building) and ZEB (Zero Energy Building) levels. In this thesis, typical Portuguese energy rehabilitation solutions are studied, as well as their comparison with the measures proposed by the MORE-CONNECT project for a pilot building in Portugal. This project consists on the development of prefabricated panels for the renovation of the building’s facade. These elements not only help to improve the thermal performance of the building, but also have reduced costs and have a short application time. The main goal of this dissertation is to evaluate the viability of the measures proposed by the MORE-CONNECT project and understand if they promote the 2020 goals of the European Union.

Dissertação de mestrado integrado em Engenharia Civil, O setor da construção é responsável por grande parte da extração de materiais, além de contribuir de forma muito significativa para os impactes ambientais que afetam o planeta. Cada vez mais o termo construção sustentável é utilizado e o desempenho energético dos edifícios torna-se um dos aspetos fundamentais quer na construção nova como na reabilitação. É neste contexto que surge a necessidade de uma metodologia que permita determinar desde as fases mais preliminares de projeto, não só as necessidades energéticas associadas a um edifício, mas também os impactes ambientais. Com base nessa metodologia surge a presente dissertação, que pretendeu numa primeira fase verificar a fiabilidade de uma metodologia desenvolvida num trabalho de investigação anterior e designada por “Metodologia para a análise integrada dos impactes ambientais e do desempenho energético de cenários de reabilitação energética de edifícios”. Numa segunda fase aplicou-se a mesma a um caso de estudo por forma a relacionar o potencial de aquecimento global e a energia durante a fase de utilização em diferentes cenários de reabilitação. Esta análise tem como objetivo determinar, para diferentes tipos de materiais de isolamento e equipamentos de climatização e preparação de águas quentes sanitárias, o cenário que otimiza a relação entre as emissões de gases de efeito de estufa e o consumo energético durante a fase de utilização. De modo a verificar a influência do contexto climático nos resultados obtidos, admitiu-se que o edifício estaria implantado em quatro cidades distintas de Portugal, tentando assim abranger todas as combinações de zonas climáticas possíveis. Este estudo surge na sequência do que foi descrito acima e tendo em conta que até ao momento nenhum estudo do género se havia ainda realizado, apenas estudos semelhantes mas a relacionar o custo com a energia., The construction sector is responsible for much of the extraction of materials, while contributing very significantly to the environmental impacts affecting the planet. Therefore the concept sustainable construction is gaining importance and the energy efficiency in buildings become one of the fundamental aspects either in new construction or in buildings’ rehabilitation. It is in this context there is a the need for a methodology that allows assessing both the energy needs of a building and the related environmental impacts, since the most preliminary stages of design. Based in a methodology called “Methodology for the integrated analysis of environmental impacts and the energy performance of energy rehabilitation scenarios of buildings", previously developed in a research work, this thesis is aimed at: i) verifying the reliability of the methodology previously developed through its application to a case study located in different climate locations; ii) to study the relation between the global warming potential and the operational energy consumption for various rehabilitation scenarios. This analysis is aimed at assessing, for different insulation materials and acclimatization and hot water preparation equipment, the rehabilitation scenario that optimizes the relation between global warming potential emission and operational energy consumption. In order to assess the influence of the climate context in the results, it is considered that the case study building is located in four different Portuguese cities, covering all areas of possible climate combinations. This study follows the studies developed before in the research center and until now there are no studied published in the same field. There are only similar studies that relate the cost of different rehabilitation scenario with life-cycle energy consumption.

Dissertação de mestrado integrado em Engenharia Civil, Com o passar do século XX e em virtude de um crescimento populacional exponencial a nível global, a indústria da construção no geral sofreu grandes alterações que contribuíram em enorme escala para o consumo desmedido de recursos naturais, a degradação de ecossistemas, a produção excessiva de resíduos, a poluição atmosférica e consequente degradação do planeta. Como consequência, ainda existe atualmente uma grande dependência dos combustíveis fósseis que, juntamente com as elevadas necessidades energéticas da indústria da construção, levou a uma dependência energética externa na UE. Neste contexto têm vindo a ser feitos esforços para a redução do impacto da indústria da construção na deterioração do planeta e na dependência energética externa, sendo o decréscimo do consumo e a alteração das fontes de energia utilizadas nos edifícios parte essencial da solução. Como tal, a reabilitação energética é fundamental na redução do consumo energético. É fulcral o estudo da reabilitação energética não só numa vertente de obtenção da maior rentabilidade possível, mas também no sentido de alcançar os níveis de custo ótimo de rentabilidade. A realização da presente dissertação tem como objetivo a avaliação das melhores soluções de reabilitação energética no setor da construção à luz da metodologia europeia de cálculo dos níveis ótimos de rentabilidade. O estudo é direcionado ao cálculo das soluções de custo ótimo de edifícios residenciais multifamiliares. Através da utilização da metodologia é obtida a otimização de custos, consumos energéticos e emissão de gases de efeitos de estufa para edifícios residenciais multifamiliares. Em suma, a meta a atingir com esta dissertação é a identificação dos níveis ótimos de rentabilidade do desempenho energético para alguns edifícios multifamiliares em Portugal., Over the last century and due to the exponential population growth worlwide, the construction industry has undergone major changes that contributed in large scale to the excessive consumption of natural resources, ecosystem degradation, excessive waste generation, air pollution and consequent degradation of the planet. As a result, there is currently a large dependency on fossil fuels, which together with the high demand of energy of the construction industry, led to an external energy dependency in the EU. In this context, efforts have been made to reduce the impact of the construction industry on the deterioration of the planet and external energy dependency, being the decrease in energy consumption and the change of energy sources used in the buildings an essential part of the solution. As such, energy rehabilitation is assumed as a fundamental piece for reducing energy consumption. It is crucial to study the energy rehabilitation not only as a mean of achieving higher profitability, but also in order to achieve more adequate primary energy consumption levels in response to future requirements. This work has as main purpose the evaluation of the best energy efficiency measures in construction industry obtained under the application of the European methodology for the calculation of cost optimal levels. This study used the methodology for the calculation of cost optimal solutions in residential multifamily buildings. With this methodology, the cost optimal solutions, the energy consumption and greenhouse gas emissions in multifamily building were obtained. So, the goal to achieve with this study was the identification of the cost optimal levels of profitability in the energy performance of some multifamily buildings in Portugal.

Dissertação de mestrado em Construção e Reabilitação Sustentáveis, Atualmente, no sector dos edifícios, verifica-se um consumo de 40 % da energia total na União Europeia (EU) e com a continuação do crescimento desse sector, prevê-se um aumento do consumo de energia, sendo por isso necessário implementar medidas para a redução do consumo da mesma, aumentando a eficiência na sua utilização e utilizando fontes renováveis para reduzir a dependência energética e emissões de gases com efeitos de estufa. Neste contexto, a Diretiva Europeia 2010/31/UE de 19 de Maio de 2010 relativa ao desempenho energético dos edifícios (EPBD recast) introduz medidas importantes para a redução da dependência energética da UE e das emissões de gases com efeito de estufa. Com a EPBD Recast, os Estados-Membros deverão garantir que os requisitos mínimos de desempenho energético são assegurados com níveis de rentabilidade ótimos, ou seja, com o custo mínimo considerando todo o seu ciclo de vida. Esta dissertação pretende determinar os níveis ótimos de rentabilidade dos requisitos mínimos de desempenho energético na reabilitação de um edifício unifamiliar de referência que é representativo da construção característica da época anterior ao ano de 1960, mediante o cálculo do custo de implementação de medidas de eficiência energética, bem como do custo de utilização do edifício durante o ciclo de vida económico estimado. É avaliada a variação dos níveis ótimos de rentabilidade na reabilitação de edifícios unifamiliares nessa época, localizados em várias regiões do país com diferentes condições climáticas. É caracterizado o parque edificado em Portugal e identificadas as medidas de melhoria para a reabilitação em duas vertentes diferentes: atuando na envolvente e atuando nos equipamentos de aquecimento, arrefecimento e aquecimento de águas sanitárias. São quantificados os custos globais associados a cada uma das variantes constituídas por combinações de medidas de melhoria ao nível da envolvente opaca e com a utilização de diferentes equipamentos de climatização e AQS, para conseguir que o desempenho energético do edifício ou da sua parte renovada seja melhorado, de forma a cumprir os requisitos mínimos de desempenho energético de edifícios e alcançar os níveis ótimos de rentabilidade. Finalmente conclui-se sobre quais as variantes mais vantajosas a nível de custo/beneficio a utilizar na reabilitação de edifícios de habitação com as mesmas características do edifício de referência, típicas da construção anterior ao ano 1960 em Portugal., Currently, in the buildings sector, there is a 40% consumption of total energy in the EU and with the continued growth of this sector, there is an increase for energy consumption and it is therefore necessary to implement measures for the reduction of consumption, improving the efficiency in its use and using renewable sources to reduce energy dependency and emissions of greenhouse gases. In this way, European Directive 2010/31/EU of May 19, 2010 on the energy performance of buildings (EPBD recast) introduces important steps required to reduce EU energy dependency and emissions of greenhouse gases. With the EPBD Recast Member States shall ensure that minimum energy performance requirements are assured with good profitability levels, i.e. with minimum cost considering the entire life cycle. This thesis aims to determine the cost optimal levels of the minimum energy performance requirements in the renovation of a reference single-family building that represents the Portuguese construction before 1960, by calculating the cost of implementing energy efficiency measures, as well as the cost of using the building during the estimated economic life cycle. The variation of the cost optimal levels in the renovation of single-family buildings from the chosen period, located in various regions with different climatic conditions is evaluated. The residential building stock in Portugal is characterized and the improvement measures for renovation in are identified, including measures to improve the building envelope and also acting in the building systems for heating, cooling and domestic hot water (DHW). The overall costs associated with each of the combinations of measures to improve the energy performance of the bulding envelope and for the use of different AVAC and DHW systems is quantified, to get the energy performance of the building or the renovated part improved in order to meet minimum energy performance requirements for buildings in order to achieve cost optimal levels. Finally, it is identified the most advantageous combinations in terms of cost / benefit to use in the renovation of residential buildings with the same characteristics of the reference building, typical of pre-1960 construction in Portugal.

Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Construções), Portugal foi alvo de uma grande evolução no mercado da construção. Com a aprovação de novos regulamentos, cada vez mais abrangentes quer a nível estrutural, quer a nível do conforto do utilizador, e a entrada na Comunidade Económica Europeia construiu-se cada vez mais, suprindo assim a necessidade de habitações para os Portugueses. No entanto, olhando para a situação atual do país e do planeta verifica-se que a maioria dos edifícios necessita de intervenção para os tornarem mais eficientes e sustentáveis, ou seja, é necessário reabilitar. No entanto, verifica-se que, para os edifícios existentes, a informação relativa à reabilitação energética e sustentável é quase nula. No intuito de contrariar esta situação e de promover a reabilitação têm surgido projetos como o Annex 56, no qual esta Dissertação se insere, que propõe desenvolver regras e procedimentos, como base para as futuras normas, de forma a permitir a reabilitação com um custo otimizado e dentro dos compromissos internacionais para reduzir as emissões de gases de efeito estufa, ou mesmo, para emissões quase zero. A Dissertação abordou este tema analisando um caso de estudo de grandes dimensões, 242 frações, na vertente da eficiência térmico-energética e da sustentabilidade. A análise da eficiência térmico-energética foi feita recorrendo ao Regulamento das Características de Comportamento Térmico dos Edifícios e a da sustentabilidade ao Guia de avaliação da metodologia SBToolH-PT. Foi feito o estudo anterior à reabilitação e, posteriormente, baseada nos resultados obtidos, foram feitas propostas de reabilitação que foram estudadas de forma a ilustrar quais seriam as mais eficientes. No final pretende-se chegar a uma metodologia que auxilie o processo de tomada de decisões para o projeto de reabilitação., The construction market in Portugal experienced a big evolution with the approval of new regulations and the entrance in the European Economic Community. The rhythm that construction took decreased the Portuguese shortage in houses, but, looking at the current situation of the country and the planet it’s visible that the majority of the buildings require intervention so they can become more efficient and sustainable. However, for the existing buildings, the information concerning the energetic and sustainable rehabilitation it’s almost none existing. In order to mend this situation projects like the Annex 56 have been appearing. Annex 56 wants to develop rules and procedures, as the basis for future standards, enabling cost effective rehabilitation of existing buildings within the international commitments to reduce greenhouse gas emissions and climate change mitigation. This implies rehabilitation towards nearly-zero emission buildings. The Dissertation will address this issue by analyzing a case study with 242 fractions, studying the thermal-energy efficiency and sustainability. The thermal-energy efficiency will be analyzed using the Thermal Performance Building Regulation and the sustainability using SBToolPT-H. Analysis will be made prior to rehabilitation and based on the results rehabilitation proposals will be made and studied in order to illustrate what will be more efficient. In the end it’s intended to achieve a methodology to assist in the decision making process for the rehabilitation project.