scholarly journals Sustainable Urban Regeneration through Densification Strategies: The Kallithea District in Athens as a Pilot Case Study

2020 ◽  
Vol 12 (22) ◽  
pp. 9462
Author(s):  
Annarita Ferrante ◽  
Anastasia Fotopoulou ◽  
Cecilia Mazzoli

The current main issue in the construction sector in Europe concerns the energy refurbishment and the reactivation of investments in existing buildings. Guidance for enhancing energy efficiency and encouraging member states to create a market for deep renovation is provided by a number of European policies. Innovative methods and strategies are required to attract and involve citizens and main stakeholders to undertake buildings’ renovation processes, which actually account for just 1% of the total building stock. This contribution proposes technical and financial solutions for the promotion of energy efficient, safe, and attractive retrofit interventions based on the creation of volumetric additions combined with renewable energy sources. This paper focuses on the urban reality of Athens as being an important example of a degraded urban center with a heavy heat island, a quite important heating demand, and a strong seismic vulnerability. The design solutions presented here demonstrate that the strategy of additions, because of the consequent increased value of the buildings, could represent an effective densification policy for the renovation of existing urban settings. Hence, the aim is to trigger regulatory and market reforms with the aim to boost the revolution towards nearly zero energy buildings for the existing building stocks.

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2472
Author(s):  
Karel Struhala ◽  
Milan Ostrý

Contemporary research stresses the need to reduce mankind’s environmental impacts and achieve sustainability. One of the keys to this is the construction sector. New buildings have to comply with strict limits regarding resource consumption (energy, water use, etc.). However, they make up only a fraction of the existing building stock. Renovations of existing buildings are therefore essential for the reduction of the environmental impacts in the construction sector. This paper illustrates the situation using a case study of a rural terraced house in a village near Brno, Czech Republic. It compares the life-cycle assessment (LCA) of the original house and its proposed renovation as well as demolition followed by new construction. The LCA covers both the initial embodied environmental impacts (EEIs) and the 60-year operation of the house with several variants of energy sources. The results show that the proposed renovation would reduce overall environmental impacts (OEIs) of the house by up to 90% and the demolition and new construction by up to 93% depending on the selected energy sources. As such, the results confirm the importance of renovations and the installation of environmentally-friendly energy sources for achieving sustainability in the construction sector. They also show the desirability of the replacement of inefficient old buildings by new construction in specific cases.


2021 ◽  
Vol 11 (1) ◽  
pp. 433
Author(s):  
Francisco José Sánchez de la Flor ◽  
Enrique Ángel Rodríguez Jara ◽  
Álvaro Ruiz Pardo ◽  
José Manuel Salmerón Lissén ◽  
Maria Kolokotroni

Buildings are known to be responsible for about a third of energy consumption in developed countries. This situation, together with the fact that the existing building stock is being renovated at a very slow pace, makes it crucial to focus on the energy retrofitting of buildings as the only way to reduce their contribution to these energy consumptions and the consequences derived from them in terms of pollution and climate change. The same level of insulation and the same type of windows is usually proposed for all dwellings in a building block. This article shows that since the improvements required by each dwelling in the same block are different, the proposed solution must also be different. The methodology is proposed for a practical case consisting of an apartment block in Cádiz, a demonstration building of the European RECO2ST project. To achieve the optimum solution for each case, a multi-objective optimization problem is solved: to minimize the annual heating demand of the building and the standard deviation of the annual demand of the different dwellings. Thanks to the use of the proposed methodology, it is possible to bring the building to a Nearly Zero Energy Building (NZEB) level, while avoiding excessive insulation that causes overheating in summer.


2021 ◽  
Vol 11 (9) ◽  
pp. 4141
Author(s):  
Yovko Ivanov Antonov ◽  
Per Kvols Heiselberg ◽  
Michal Zbigniew Pomianowski

Reaching environmental targets set by the European Union (EU) requires a constant renovation of the existing building stock to nearly Zero Energy Buildings (NZEB) in a cost-optimal manner. Studies show that the renovation rate of the existing building stock is more than two times less than what is necessary to reach the targets. Furthermore, the majority of performed renovations across the EU reach just a small amount of energy savings, whereas NZEB renovations are rarely achieved. This paper proposes a methodology for the evaluation of renovation measures, aiming to provide decision support related to the selection of what to renovate and to what extent. The proposed method is rooted in the well-established cost-optimal methodology, yet it suggests a pre-step to package evaluation. This is done by means of a simplified cost-effective parameter (CEP), linking cost, lifetime, and energy savings. The methodology is demonstrated using a case study building in Denmark. The results show that the CEP provides good grounds for the compilation of single actions to packages. Further developments could focus on the sensitivity of the model inputs and integration of additional evaluation parameters to cost, such as environmental, architectural, comfort, risk, etc.


2019 ◽  
Vol 18 (1) ◽  
pp. 270-292
Author(s):  
John Dadzie ◽  
Goran Runeson ◽  
Grace Ding

Purpose Estimates show that close to 90% of the buildings we will need in 2050 are already built and occupied. The increase in the existing building stock has affected energy consumption thereby negatively impacting the environment. The purpose of this paper is to assess determinants of sustainable upgrade of existing buildings through the adoption and application of sustainable technologies. The study also ranks sustainable technologies adopted by the professionals who participated in the survey with an in-built case study. Design/methodology/approach As part of the overall methodology, a detailed literature review on the nature and characteristics of sustainable upgrade and the sustainable technologies adopted was undertaken. A survey questionnaire with an in-built case study was designed to examine all the sustainable technologies adopted to improve energy consumption in Australia. The survey was administered to sustainability consultants, architects, quantity surveyors, facility managers and engineers in Australia. Findings The results show a total of 24 technologies which are mostly adopted to improve energy consumption in existing buildings. A factor analysis shows the main components as: lighting and automation, heating, ventilation and air conditioning (HAVC) systems and equipment, envelope, renewable energy and passive technologies. Originality/value The findings bridge the gap in the literature on the adoption and application of sustainable technologies to upgrade existing buildings. The technologies can be adopted to reduce the excessive energy consumption patterns in existing buildings.


2021 ◽  
Vol 246 ◽  
pp. 13005
Author(s):  
Terttu Vainio ◽  
Eero Nippala ◽  
Timo Kauppinen

The Energy Performance of Buildings Directive together with the Energy Efficiency Directive and Renewable Energy Sources Directive define the frame and target state for energy performance of the existing building stock. This should be very energy efficient and decarbonised by 2050. The Finnish target is more ambitious, to achieve the target state already in 2035. In this paper, we discuss and concretise the role of HVAC in overcoming the challenge. Buildings in the Nordic countries are already very energy efficient. Structural improvements of energy efficiency are relatively expensive and have limited potential for energy saving. The best cost-benefit ratio can be obtained by combining HVAC with dynamic building automation systems. Also the EPBD calls for improvement of building automation systems and related measurements in new as well as existing buildings. The performance of buildings can be verified and deviations can be detected by monitoring-based commissioning during their life cycle. This means that special attention must be paid to the instrumentation level and an improved online reporting system for stakeholders. As a conclusion, we see that HVAC systems are in a key role in decarbonisation of existing buildings and a strategic sector on the way to a carbon-neutral society.


2016 ◽  
Vol 824 ◽  
pp. 469-476
Author(s):  
Attila Talamon ◽  
Viktória Sugár ◽  
Ferenc Pusztai

There is an urgent need nowadays to reduce current levels of GHGs emissions. On the other hand the EU countries are largely dependent on energy imports and are vulnerable to disruption in energy supply which may in turn threaten the functioning of their current economic structure. The EU imported 54% of its energy sources in 2006 and this value was projected to increase even further by 2030. Reducing its import dependency is one of the EU’s main goals of the 20-20 by 2020 target – this legislative package is believed to reduce the expected imports of energy by 26% compared to the development before the 20-20 initiative.One of the most important environmental problems is the energy consumption of the buildings. Current paper shows that buildings built with industrialized technology can deliver large energy and GHG emission reductions at low costs.Only 1-2% part of the building stock is exchanged every year, so it is very important to increase the energy efficiency of the existing buildings, too.Present paper focuses on the buildings built with industrialized technology only, and their potential in nearly zero-energy buildings sector. Up till now the Central European support schemes concentrated most financial resources on buildings built with prefabricated technology. Present paper explains the past and present of the “panel” problem in Hungary with a short outlook to some other countries.


Author(s):  
Annarita Ferrante ◽  
Fabrizio Ungaro ◽  
Giovanni Semprini ◽  
Lorna Dragonetti ◽  
Elettra Agliardi ◽  
...  

<p>and international projects</p><p>various EU H2020 projects</p><p>Though housing is one of the most energy consumer sectors, it is currently extremely underestimated, because of a clear investment gap due to economic, social and legislative barriers. The EU project ABRACADABRA (Assistant Building to Retrofit, Adopt, Cure And Develop the Actual Buildings up to zeRo energy, Activating a market for deep renovation) is based on the idea that the real estate value increase given by the appropriate densification strategy in urban environments could be an opportunity to activate a market for deep energy renovation. To prove the effectiveness of the strategy more than 70 case studies throughout the EU cities have been assessed by means of a cost-effective analysis. Basing on the parametric variation of the different values involved (cost of construction, energy, etc.) the benefit of this strategy has been proved in the majority of the different building types and contexts.</p><p>More interestingly, the ABRA strategy has been simulated and tested outside Europe in order to verify its scalability and the possibility of considering other non-energy related benefits in the renovation of the existing building stock. A specific study on the NYC urban context has been conducted to effectively adapt the strategy and combine the global drivers of energy consumption reduction and CO<span>2</span> emission reduction with the local need of combating flood emergency and related flood-proofing measures.</p><p>The results reached by this work demonstrate how the energy retrofit trough add-ons reduces significantly the payback times of the investments, preserve soil consumption, while providing a extraordinary opportunity to enhance urban resiliency by challenging the local emergencies.</p>


Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 639 ◽  
Author(s):  
Francesco Nocera ◽  
Salvatore Giuffrida ◽  
Maria Rosa Trovato ◽  
Antonio Gagliano

The paper addresses an important long-standing question in regards to the energy efficiency renovation of existing buildings, in this case hotels, towards nearly zero-energy (nZEBs) status. The renovation of existing hotels to achieve a nearly zero-energy (nZEBs) performance is one of the forefront goals of EU’s energy policy for 2050. The achievement of nZEBs target for hotels is necessary not only to comply with changing regulations and legislations, but also to foster competitiveness to secure new funding. Indeed, the nZEB hotel status allows for the reduction of operating costs and the increase of energy security, meeting the market and guests’ expectations. Actually, there is not a set national value of nZEBs for hotels to be attained, despite the fact that hotels are among the most energy-intensive buildings. This paper presents the case study of the energy retrofit of an existing historical hotel located in southern Italy (Syracuse) in order to achieve nZEBs status. Starting from the energy audit, the paper proposes a step-by-step approach to nZEBs performance, with a perspective on the costs, in order to identify the most effective energy solutions. Such an approach allows useful insights regarding energy and economic–financial strategies for achieving nZEBs standards to highlighted. Moreover, the results of this paper provide, to stakeholders, useful information for quantifying the technical convenience and economic profitability to reach an nZEBs target in order to prevent the expenses necessary by future energy retrofit programs.


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