Construction cost and energy consumption resulting from energy retrofitting in an apartment building in Madrid (Spain) (original) (raw)
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The paper reports a research started with a simple case study and a simple question. The case study is an Italian social housing quarter, served by a district heating system, which needs – as many others in many other countries – a reasonable refurbishment. The question is: «may savings, derived from its energy retrofit, pay refurbishment costs?». In order to answer to this question, we studied the economic sustainability of different retrofitting strategies and assessed their Return of Investment. In the first phase of the work, design choices were roughly defined, with a sketch of basic details and a rough energy demand calculation, according to national standards. In the second phase, design choices were detailed in order to have a reliable assessment of costs of each refurbishment strategy and to investigated the most probable impact of thermal bridges (balconies, windows, pillars, beams, etc.) on the real energy consumption for heating and, consequently, on the Return of the In...
Under the current Energy Performance of Buildings Directive, EU countries must set building energy renovation as a goal for future development of the cities. The 22@ district of Barcelona is one of the most thriving innovation districts of Europe with an increasing market for office buildings. In this framework, the present paper evaluates the effectiveness of a series of strategies considered the real case project of the energy retrofit of an existing building in 22@. In particular, the study presents the results of different scenarios of building retrofits, where simulations of dynamic envelopes are performed, with the inclusion of a conventional ventilated façade, Living Green Walls and Phase Change Material (PCM) for thermal energy storage. The different scenarios are compared in terms of energy performance, enhanced comfort and cost-benefit analysis. The benefits of latent thermal energy storage, improved thermal inertia and evapotranspiration of the vegetated elements are also assessed. Eventually this study helps understanding the feasibility of the implementation of the nZEB standard in energy retrofit of buildings in the specific context of Barcelona and Spain. 1. Introduction The massive urban development is altering the land surface by concentrating materials which effectively retain heat and create impervious surfaces, thus affecting urban local climate and urban hydrology. Moreover, tall buildings provide multiple surfaces for the absorption of solar radiation that is subsequently reradiated as heat, thus enhancing the efficiency with which urban areas are warmed up [1]. Building renovation is a main issue of recent European policies towards energy efficiency. Today's renovation projects have the challenges of improving the energy efficiency in order to reach the goals of zero emission in the building sector while improving their social and economic value, securing a sustainable use of resources [2] and minimizing the deleterious effects of buildings in the urban environment. The renovation of the building envelope, are a key factor in the energy rehabilitation of buildings and the urban environment. This paper describes three renovation strategies: living walls, ventilated facades with fibre-cement cladding and ventilated facades with PCM materials [3,4,5].
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The application of the European directives related to the energy consumption of existing buildings leads to the integration of efficient techniques into the refurbishment actions. This procedure allows reaching high energy savings and reducing pollutant emissions. The identification of the energy consumption profile of the building stocks is a necessary step to evaluate the impact of retrofit measures. With this aim, the energy performance of representative dwellings has been analyzed to develop a citizen-oriented platform. This representativeness has been chosen through one parametric matrix that characterizes the residential building stock of Madrid. Different refurbishment strategies have been highlighted to assess the energy savings in comparison with the initial situation. Two building cases and three boundary conditions have been selected to develop six TRNSYS models. The energy impact produced by the implementation of selected refurbishment strategies has been evaluated through a sensitivity analysis. Batteries of simulations have been executed coupling the TRNSYS models with GenOpt. The most influential strategies are the typology of façades, insulation at the roof, variable set point temperatures, better glazing and exterior summer shading over the windows. Building performances to minimize the annual thermal needs and one economic study have been developed.
Energy conservation by retrofitting of dwellings
E3S Web of Conferences
This article investigates the impact of energy renovation on the indoor environmental quality of apartment building during heating season. The study was performed in one residential building before and after its renovation. Energy auditing and classification of the selected building into energy classes were carried out. Additionally, evaluation of indoor air quality was performed using objective measurements and subjective survey. Thermal environment and concentration of CO2 was measured in bedrooms. Higher concentrations of CO2 was observed in the residential building after its renovation. The concentrations of CO2, in some cases exceeded the recommended maximum limits, especially after implementing of energy saving measures on the building. The average air exchange rate was visible higher before renovation of the building. The current study indicates that large-scale of renovations may reduce the quality of the indoor environment in many apartments, especially in the winter season.
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This paper describes the implementation of an integrated cost optimality and environmental assessment involving alternative energy efficiency retrofit packages for a building that dates from the beginning of the 20th century. A building typical of the building stock in the centre of Coimbra (located in the central region of Portugal and recently classified as a UNESCO World Heritage Site) was used to illustrate the methodology presented. The results were also analysed for the same building in two other locations. A life-cycle (LC) model was implemented to assess different energy efficiency measures for an apartment. The economic assessment complied with European Directive 2010/31/EU. The results show that the lowest life-cycle environmental impacts were obtained for insulation thicknesses between 50 and 120 mm, which are also cost-optimal. It is also shown that insulation thicknesses of more than 80 mm do not improve energy efficiency or global cost reduction. This paper shows that, even though historic buildings in Portugal do not have to comply with building energy codes, significant energy savings can be achieved for them without changing their historic character. It was also concluded that economic and environmental costs can both be minimised by choosing the most suitable energy efficiency retrofit measures.
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Nowadays, energy retrofit interventions on the existing building stock are of paramount importance towards energy consumption and emissions reductions in the construction sector. Such interventions are also crucial in the view of increasing cities resilience with respect to the intensification of frequent extreme weather events, such as cold spells and heatwaves. Indeed, a wide portion of our cities is dated and lacking with respect to performances. These are the motivations behind the proposed sustainable approach, which deals with the environmental perspective, but also with social and economic ones, by proposing the retrofit of the Public Residential Building stock (Edilizia Residenziale Pubblica, ERP). The objective is to improve the energy performance of ERP stock by means of construction materials coming from local km0 agricultural waste and by-products. The research was conducted by means of in field and numerical analyses of the energy performances of a relevant case study b...
Indoor and Built Environment, 2018
Upgrading the energy efficiency of existing buildings is a well-known issue around the globe. Given the very low renewal rate of the building stock, thermal retrofit of the existing buildings seems to be a good solution to improve the environmental performance of the building sector. Several studies have acknowledged the lack of knowledge, experience and best-practice examples as barriers in thermal retrofit of existing buildings. Therefore, this study has focused on developing recommendations on the most effective and feasible retrofitting techniques for existing buildings and performing financial analysis of initial investment vs return based on the quantitative results of the energy modelling. Thermal comfort modelling software FirstRate5 has been used to simulate the annual heating and cooling energy consumption of nine benchmark buildings through a range of retrofitting techniques. Dwellings of varying construction materials including weatherboard, cavity brick and brick veneer have been simulated to improve accuracy. Examining seven different thermal retrofitting options in this study, it has become apparent that there is significant heating and cooling energy reduction, with payback period of less than three years, by implementing two options of the examined retrofitting cases to existing residential dwellings.
Sustainable Construction: Energy Efficiency in Residential Buildings
ABSTRACT: The high consumption in the buildings sector, in Portugal, implies an obstacle to the accomplishment of the purposes intrinsic to sustainable construction. To change this situation we must encourage the construction of energy efficient buildings based on a set of solutions that strive to reduce the energy consumption of buildings throughout its life cycle, while ensuring comfort for its occupants. The main objective of this article is to analyze proposals that improve energy efficiency in residential buildings, based on the calculation of energy savings associated with the use of air conditioning (to assure a certain comfort temperature) and their payback period. To this end a case study was established. The energy performance assessment, before and after the implementation of the improvement strategies, was done trough a dynamic analysis with the EnergyPlus software. The use of the considered strategies improves the energy efficiency of buildings, such as the case study, with different payback periods.
Energy and Buildings, 2008
Some of the problems associated with assessing the retrofit effectiveness of apartment buildings in urban areas are considered. The retrofit of houses should be followed by the amelioration of their surroundings. The priority order of districts to be renovated depends on the condition of the buildings in a district and on strategic urban development programmes. In order to determine the profitability of investments in housing retrofit, a number of retrofit scenarios should be developed. The authors of this paper offer a new approach to determining the retrofit effectiveness of houses based both on expected energy savings and the increase in market value of renovated buildings. In line with the proposed approach, retrofit scenarios for apartment buildings in Vilnius were developed, i.e. retrofit investment packages for various districts were prepared and arranged in the priority order for their application according to the method of geographical analysis suggested by the authors. # development of society . Coherent and efficient retrofit scenarios are commonly based on a building's state of degradation and its obsolescence. An advanced method, based on multicriteria analysis, also helps design effective retrofit scenarios . Before a decision is made to proceed with any project of building retrofit, a brief but reliable report is needed describing the current state of the building and estimating the cost of building operations to be performed . The developed methodology and software apply to specific refurbishment work and cost assessment of building renovation needs with respect to energy conservation and improvement of the indoor environment.
Energy Procedia, 2014
May energy saving derived from the retrofit of a building be able to pay its costs? The paper wants to answer to this simple question, reporting a research started with a simple case study (an Italian social housing quarter, served by a district heating system, which needs -as many others in many other countries -a reasonable refurbishment). The economic sustainability of different retrofitting strategies has been studied: a method to evaluate the costs of refurbishment interventions has been developed through a detailed design of interventions, identifying construction costs thanks to the contribution of a group of selected contractors which gave us reasonable prices representative of a real services offers and assessing the cost-optimal energy levels leading the building towards the energy labels B and A. Both envelope and systems refurbishment works have been investigated. The adopted method allows to chose among different refurbishment options, evaluating them as elementary cases and whole interventions, considering their efficiency by means of the Cost of Conserved Energy (CCE) method and the pay-back of the investments (ROI) by the cash-flow method, analysing different funding systems and incentives.