This page has only limited features, please log in for full access.
In European countries, buildings are the major energy consumers due to the general low energy performance of the existing building stock. To achieve the ambitioned targets for emissions reduction, it will be necessary to take actions for its large scale renovation. However, today's standards are mainly focused on new buildings, guiding the improvement of the energy performance of the existing buildings into expensive processes and complex procedures that seldom are accepted by users, owners or promoters. For these buildings, the range of technical solutions is shorter and may lead to ancillary works that result in a relevant increase in costs. In this context, the IEA EBC Programme launched the Annex56 project, with the goal of investigating solutions and produce guidance suitable for European residential buildings, taking into consideration not only the benefits related to energy and emissions reduction, but also the added value resulting from the renovation process. Considering the goal of reducing emissions, measures that promote the use of renewable energy can be as effective as energy efficiency measures, therefore, it is important to determine the optimal balance between the minimization of energy demand and the use of renewable energy. The optimization process has to explore the full range of cost-effective reduction of emissions and energy use and also to take into account the additional benefits and the overall added value achieved by the building within the renovation process as well as the increasing relevance of the embodied energy associated to the materials and systems used in the interventions.
Manuela Almeida; Marco Ferreira. Ten questions concerning cost-effective energy and carbon emissions optimization in building renovation. Building and Environment 2018, 143, 15 -23.
AMA StyleManuela Almeida, Marco Ferreira. Ten questions concerning cost-effective energy and carbon emissions optimization in building renovation. Building and Environment. 2018; 143 ():15-23.
Chicago/Turabian StyleManuela Almeida; Marco Ferreira. 2018. "Ten questions concerning cost-effective energy and carbon emissions optimization in building renovation." Building and Environment 143, no. : 15-23.
The construction sector is facing increasingly strict energy efficiency regulations. Existing buildings have specific technical, functional and economic constraints, which, in fulfilling regulations, could lead to costly and complex renovation procedures and also lead to missed opportunities for improving their energy performance. In this article, the methodology for comparing cost-optimality in building renovations, developed in the International Energy Agency (IEA)–Energy in Buildings and Communities (EBC) Annex 56 project, is extended with a life cycle assessment by including embodied primary energy and carbon emissions in the calculations. The objective is to understand the relevance of embodied energy and carbon emissions in the evaluation of the cost effectiveness of building renovation solutions towards nearly zero energy buildings, as well as the effect of the embodied values in the achievable carbon emissions and primary energy reductions expected in an energy renovation. Results from six case studies, representative of different regions in Europe, suggest that embodied values of energy and carbon emissions have a decreasing effect—ranging from 2 to 32%—on the potential reductions of energy and emissions that can be achieved with renovation measures in buildings. In addition, the consideration of the embodied energy and carbon emissions does not affect the ranking of the renovation packages.
Manuela Almeida; Marco Ferreira; Ricardo Barbosa. Relevance of Embodied Energy and Carbon Emissions on Assessing Cost Effectiveness in Building Renovation—Contribution from the Analysis of Case Studies in Six European Countries. Buildings 2018, 8, 103 .
AMA StyleManuela Almeida, Marco Ferreira, Ricardo Barbosa. Relevance of Embodied Energy and Carbon Emissions on Assessing Cost Effectiveness in Building Renovation—Contribution from the Analysis of Case Studies in Six European Countries. Buildings. 2018; 8 (8):103.
Chicago/Turabian StyleManuela Almeida; Marco Ferreira; Ricardo Barbosa. 2018. "Relevance of Embodied Energy and Carbon Emissions on Assessing Cost Effectiveness in Building Renovation—Contribution from the Analysis of Case Studies in Six European Countries." Buildings 8, no. 8: 103.
In Europe, the latest updates in the directive on the energy performance of buildings introduced two fundamental concepts, namely the cost-optimal energy requirements and the nearly-zero energy buildings (nZEB). Although these concepts are related, the cost-optimal is focused on costs while the nZEB prioritise the energy performance and the use of renewable energy harvested on site. To understand how these two concepts can be articulated to potentiate energy savings in the Portuguese building stock, reference buildings representative of the residential building stock were analysed. This allowed comparing the cost-optimal renovation packages with the ones that lead to near the zero energy levels, with the lowest costs. This evaluation clarifies on how far it is possible to go in a cost-effective way on a renovation process when the target is zero energy and helps to pave the way for the national definition of nZEB in building renovation. The results indicate that the transition from the cost-optimality to nZEB may occur in Portugal without major efforts, being possible to integrate both concepts with nZEB being reached by adding renewable energy systems to the cost-optimal levels of the buildings’ envelope, giving support to the nZEB definition presented in the current Portuguese thermal regulation.
M. Ferreira; M. Almeida; A. Rodrigues. Cost-optimal energy efficiency levels are the first step in achieving cost effective renovation in residential buildings with a nearly-zero energy target. Energy and Buildings 2016, 133, 724 -737.
AMA StyleM. Ferreira, M. Almeida, A. Rodrigues. Cost-optimal energy efficiency levels are the first step in achieving cost effective renovation in residential buildings with a nearly-zero energy target. Energy and Buildings. 2016; 133 ():724-737.
Chicago/Turabian StyleM. Ferreira; M. Almeida; A. Rodrigues. 2016. "Cost-optimal energy efficiency levels are the first step in achieving cost effective renovation in residential buildings with a nearly-zero energy target." Energy and Buildings 133, no. : 724-737.
Many regulations and initiatives to promote the reduction of energy consumption and carbon emissions have been implemented in the building sector. However, they are mostly targeted at new buildings. In order to reach the goals that are being established, while it is necessary to implement measures in new buildings, this is doubly the case for existing buildings, which correspond to the majority of the European building stock. Building renovation improves buildings’ energy performance and reduces the carbon emissions related to the operation of the building, but this involves adding new materials and technical systems. The production process of these new materials uses energy (embodied energy) and releases carbon emissions. In this sense, to evaluate the relevance of the embodied energy in building renovation, the International Energy Agency Energy in Buildings and Communities (IEA EBC) project, Annex 56, developed a methodological framework to evaluate the cost-effectiveness of building renovation solutions that includes a life-cycle impact assessment (LCIA). Thus, using a particular case study, different renovation solutions are compared both with and without consideration of the embodied energy. The results show that the embodied energy does not have a major impact on the evaluation of the cost-effectiveness of the renovation solutions, but that as the renovation energy target gets closer to a zero non-renewable energy level, its relevance increases.
Manuela Guedes De Almeida; Ricardo Mateus; Marco António Pedrosa Santos Ferreira; Ana Rodrigues. Life-cycle costs and impacts on energy-related building renovation assessments. International Journal of Sustainable Building Technology and Urban Development 2016, 7, 206 -213.
AMA StyleManuela Guedes De Almeida, Ricardo Mateus, Marco António Pedrosa Santos Ferreira, Ana Rodrigues. Life-cycle costs and impacts on energy-related building renovation assessments. International Journal of Sustainable Building Technology and Urban Development. 2016; 7 (3-4):206-213.
Chicago/Turabian StyleManuela Guedes De Almeida; Ricardo Mateus; Marco António Pedrosa Santos Ferreira; Ana Rodrigues. 2016. "Life-cycle costs and impacts on energy-related building renovation assessments." International Journal of Sustainable Building Technology and Urban Development 7, no. 3-4: 206-213.
The relevance of the building sector in the global energy use as well as in the global carbon emissions, both in the developed and developing countries, 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 for energy and emissions saving, large scale building renovation has been found hard to trigger, mainly because present standards are mainly focused on new buildings, not responding effectively to the numerous 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 it has been long recognized that investment on energy efficiency and low carbon technologies yield several benefits beyond the value of saved energy which can be as important as the energy cost savings process. Based on the analysis of significant literature and several case studies, the relevance of co-benefits achieved in the renovation process is highlighted. These benefits can be felt at the building level by the owner or user (like increased user comfort, fewer problems with building physics, improved aesthetics) and should therefore be considered in the definition of the renovation measures, but also at the level of the society as a whole (like health effects, job creation, energy security, impact on climate change), and from this perspective, policy makers must be aware of the possible crossed impacts among different areas of the society for the development of public policies.
Marco Ferreira; Manuela Almeida. Benefits from Energy Related Building Renovation Beyond Costs, Energy and Emissions. Energy Procedia 2015, 78, 2397 -2402.
AMA StyleMarco Ferreira, Manuela Almeida. Benefits from Energy Related Building Renovation Beyond Costs, Energy and Emissions. Energy Procedia. 2015; 78 ():2397-2402.
Chicago/Turabian StyleMarco Ferreira; Manuela Almeida. 2015. "Benefits from Energy Related Building Renovation Beyond Costs, Energy and Emissions." Energy Procedia 78, no. : 2397-2402.
Building sector has become an important target for carbon emissions reduction, energy consumption and resources depletion. Due to low rates of replacement of the existing buildings, their low energy performances are a major concern. Most of the current regulations are focused on new buildings and do not account with the several technical, functional and economic constraints that have to be faced in the renovation of existing buildings. Thus, a new methodology is proposed to be used in the decision making process for energy related building renovation, allowing finding a cost-effective balance between energy consumption, carbon emissions and overall added value.
Manuela Almeida; Marco Ferreira. IEA EBC Annex56 Vision for Cost Effective Energy and Carbon Emissions Optimization in Building Renovation. Energy Procedia 2015, 78, 2409 -2414.
AMA StyleManuela Almeida, Marco Ferreira. IEA EBC Annex56 Vision for Cost Effective Energy and Carbon Emissions Optimization in Building Renovation. Energy Procedia. 2015; 78 ():2409-2414.
Chicago/Turabian StyleManuela Almeida; Marco Ferreira. 2015. "IEA EBC Annex56 Vision for Cost Effective Energy and Carbon Emissions Optimization in Building Renovation." Energy Procedia 78, no. : 2409-2414.
The recast of the European Union's 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.
Marco Ferreira; Manuela Guedes De Almeida; Ana Rodrigues; Sandra Monteiro da Silva. Comparing cost-optimal and net-zero energy targets in building retrofit. Building Research & Information 2014, 44, 188 -201.
AMA StyleMarco Ferreira, Manuela Guedes De Almeida, Ana Rodrigues, Sandra Monteiro da Silva. Comparing cost-optimal and net-zero energy targets in building retrofit. Building Research & Information. 2014; 44 (2):188-201.
Chicago/Turabian StyleMarco Ferreira; Manuela Guedes De Almeida; Ana Rodrigues; Sandra Monteiro da Silva. 2014. "Comparing cost-optimal and net-zero energy targets in building retrofit." Building Research & Information 44, no. 2: 188-201.
Marco Ferreira; Manuela Almeida; Ana Rodrigues. Cost optimality and net-zero energy in the renovation of Portuguese residential building stock – Rainha Dona Leonor neighbourhood case study. International Journal of Sustainable Building Technology and Urban Development 2014, 5, 306 -317.
AMA StyleMarco Ferreira, Manuela Almeida, Ana Rodrigues. Cost optimality and net-zero energy in the renovation of Portuguese residential building stock – Rainha Dona Leonor neighbourhood case study. International Journal of Sustainable Building Technology and Urban Development. 2014; 5 (4):306-317.
Chicago/Turabian StyleMarco Ferreira; Manuela Almeida; Ana Rodrigues. 2014. "Cost optimality and net-zero energy in the renovation of Portuguese residential building stock – Rainha Dona Leonor neighbourhood case study." International Journal of Sustainable Building Technology and Urban Development 5, no. 4: 306-317.