scholarly journals Avoiding financial lock-in effects in case of a stepwise energy renovation of social housing in Flanders

2019 ◽  
Vol 4 (2) ◽  
pp. 160-176
Author(s):  
Els Van de Moortel

Social housing companies in Flanders are facing the need for a thorough renovation of their building stock in the coming years. This renovation should be in line with the policy targets to reduce the energy use of buildings by 2050. As such thorough renovation scenarios require a high investment cost; a stepwise approach is often implemented. It is important to ensure that the overall investment cost for such a step by step approach is not (much) higher than an “in-depth at-once renovation”. This paper reports on the development of a method to support social housing companies in making a cost-optimal renovation planning for their building stock. Whereas current research focuses on net present value and payback time, this paper considers the life cycle cost for the evaluation of the investments, taking into account: (1) available financial resources over time, (2) various credit facilities over time and (3) various technical options leading to different energy savings. To check consistency and applicability, the method is tested on four case studies. Despite some uncertainties in this early development stage of the method, it is possible to draw some first conclusions based on the assessment of one case study. Since the results of the LCC assessment depend on the assumed economic parameters and expected service life of the building, those parameters have to be estimated with caution. Instead of implementing similar renovation strategies to all buildings, it would be advisable to do a Life Cycle Cost assessment per renovation project to get insight in the efficiency of the renovation strategy in order to use the limited budget of social housing companies more effectively.

2019 ◽  
Vol 11 (5) ◽  
pp. 1452 ◽  
Author(s):  
Fabio Fantozzi ◽  
Caterina Gargari ◽  
Massimo Rovai ◽  
Giacomo Salvadori

The debate on the relevance of the global sustainability (including energy, environmental, social, economic, and political aspects) of building stock is becoming increasingly important in Europe. In this context, special attention is placed on the refurbishment of existing buildings, in particular those characterized by significant volumes and poor energy performance. Directive 2012/27/EU introduced stringent constraints (often disregarded) for public administrations to ensure a minimum yearly renovation quota of its building stock. This study describes how Life Cycle Cost analysis (LCC) can be used as a tool to identify the “cost-optimal level” among different design solutions to improve the energy performance of existing buildings. With this aim, a social housing building located in the town of Pisa (Italy) was chosen as the case study, for which two alternative renovation designs were compared using the LCC methodology to identify the optimal solution. The two alternatives were characterized by the same energy performance—one was based on the demolition of the existing building and the construction of a new building (with a wooden frame structure, as proposed by the public company owner of the building), while the other was based on the renovation of the existing building. This study can provide useful information, especially for designers and public authorities, about the relevance of the economic issues related to the renovation of social housing in a Mediterranean climate.


2021 ◽  
Vol 11 (14) ◽  
pp. 6254
Author(s):  
Elena G. Dascalaki ◽  
Constantinos A. Balaras

In an effort to reduce the operational cost of their dwellings, occupants may even have to sacrifice their indoor thermal comfort conditions. Following the economic recession in Greece over recent years, homeowners have been forced to adapt their practices by shortening heating hours, lowering the indoor thermostat settings, isolating spaces that are not heated or even turning off their central heating system and using alternative local heating systems. This paper presents the results from over 100 occupant surveys using questionnaires and walk-through energy audits in Hellenic households that documented how occupants operated the heating systems in their dwellings and the resulting indoor thermal comfort conditions and actual energy use. The results indicate that the perceived winter thermal comfort conditions were satisfactory in only half of the dwellings, since the actual operating space heating periods averaged only 5 h (compared with the assumed 18 h in standard conditions), while less than half heated their entire dwellings and only a fifth maintained an indoor setpoint temperature of 20 °C, corresponding to standard comfort conditions. Mainstream energy conservation measures include system maintenance, switching to more efficient systems, reducing heat losses and installing controls. This information is then used to derive empirical adaptation factors for bridging the gap between the calculated and actual energy use, making more realistic estimates of the expected energy savings following building renovations, setting prudent targets for energy efficiency and developing effective plans toward a decarbonized building stock.


2021 ◽  
Vol 11 (4) ◽  
pp. 1423
Author(s):  
José Manuel Salmerón Lissen ◽  
Cristina Isabel Jareño Escudero ◽  
Francisco José Sánchez de la Flor ◽  
Miriam Navarro Escudero ◽  
Theoni Karlessi ◽  
...  

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.


2020 ◽  
Vol 12 (16) ◽  
pp. 6584
Author(s):  
Jingjing Jia ◽  
Shujie Ma ◽  
Yixi Xue ◽  
Deyang Kong

Electric carsharing (ECS) is a potential option to address the problem of unsustainability in the transportation sector. The business-to-consumer model of ECS, which is one of several different electric carsharing models, has gained much popularity in recent years. Generating sufficient revenue to cover costs is a critical factor for ECS companies to maintain healthy development. This study makes an economic analysis, on the basis of life-cycle cost and monetary revenue associated with the operation of ECS, of two Chinese ECS companies: EVCARD and LCCS. Based on data gathered by field investigation, this study aims to determine the break-even moment for each company’s main vehicle models by means of the net present value method. The results show that EVCARD achieved an earlier break-even moment than LCCS. The break-even moment of Chery eQ of EVCARD was the shortest of all the vehicle models, at only 181.3 min. Moreover, a sensitivity analysis was conducted to portray how different cost-related and revenue-related factors influence the break-even moment. Our findings indicate that a wide difference exists in terms of the influence of different factors on the break-even moment. Among these, the manufacturer’s suggested retail price is the most influential variable, followed by the unit rental price. The reaction of the break-even moment to the market price of a charging pile and the non-rental revenue per vehicle—especially the latter—was found to be negligible in the sensitivity analysis.


2021 ◽  
Author(s):  
Amir Fereidouni Kondri

This report presents the methodology for determining least cost energy efficient upgrade solutions in new residential housing using brute force sequential search (BFSS) method for integration into the reference house to reduce energy consumption while minimizing the net present value (NPV) of life cycle costs. The results showed that, based on the life cycle cost analysis of 30 years, the optimal upgrades resulted in the average of 19.25% (case 1), 31% (case 2a), and 21% (case 2b) reduction in annual energy consumption. Economic conditions affect the sequencing of the upgrades. In this respect the preferred upgrades to be performed in order are; domestic hot water heating, above grade wall insulation, cooling systems, ceiling insulation, floor insulation, heat recovery ventilator, basement slab insulation and below grade wall insulation. When the gas commodity pricing becomes high, the more energy efficient upgrades for domestic hot water (DHW) get selected at a cost premium.


2014 ◽  
Vol 39 (2) ◽  
pp. 48-56
Author(s):  
Tadeo Baldiri Salcedo Rahola ◽  
Ad Straub ◽  
Angela Ruiz Lázaro ◽  
Yves Galiègue

The renovation of existing building stock is seen as one the most practical ways to achieve the high energy savings targets for the built environment defined by European authorities. In France, the Grenelle environmental legislation addresses the need to renovate the building stock and specifically stresses the key role of social housing organisations. In recent years, French procurement rules have been modified in order to allow social housing organisations to make use of integrated contracts such as Design-Build-Maintain. These contracts have a greater potential to deliver energy savings in renovation projects than do traditional project delivery methods, like Design-bid-Build. This is because they facilitate collaboration between the various actors and boost their commitment to the achievement of project goals. In order to evaluate the estimated potential of such contracts to achieve energy savings, two renovation projects (carried out by two French social housing organisations) were analysed from their inception until the end of construction work. The analysis is based on written tender documents, technical evaluation reports, observations of the negotiation phase (in one of the cases) and interviews with the main actors involved. Findings show that Design-Build-Maintain contracts do indeed offer substantial energy savings. Both projects achieved higher energy targets than those initially required. Furthermore, the energy results are guaranteed by the contractor, through a system of bonuses and penalties. Other results demonstrate that, compared to previous Design-bid-Build renovation projects, these projects were completed in less time (from project inception to completion of the work) and at virtually the same cost. There has also been a substantial improvement in cooperation between the actors involved.


2018 ◽  
Vol 61 (6) ◽  
pp. 1795-1810
Author(s):  
James Bambara ◽  
Andreas K. Athienitis

Abstract. The energy consumption of a building is significantly impacted by its envelope design, particularly for greenhouses where coverings typically provide high heat and daylight transmission. Energy and life cycle cost (LCC) analysis were used to identify the most cost-effective cladding design for a greenhouse located in Ottawa, Ontario, Canada (45.4° N) that employs supplemental lighting. The base case envelope design uses single glazing, whereas the two alternative designs consist of replacing the glass with twin-wall polycarbonate and adding foil-faced rigid insulation (permanent or movable) on the interior surface of the glass. All the alternative envelope designs increased electricity consumption for lighting and decreased heating energy use except when permanent or movable insulation was applied to the north wall and in the case of permanent insulation on the north wall plus polycarbonate on the east wall. This demonstrates how the use of reflective opaque insulation on the north wall can be beneficial for redirecting light onto the crops to achieve simultaneous reductions in electricity and heating energy costs. A maximum reduction in LCC of 5.5% (net savings of approximately $130,000) was achieved when permanent insulation was applied to the north and east walls plus polycarbonate on the west wall. This alternative envelope design increased electricity consumption for horticultural lighting by 4.3%, reduced heating energy use by 15.6%, and caused greenhouse gas emissions related to energy consumption to decrease by 14.7%. This analysis demonstrates how energy and economic analysis can be employed to determine the most suitable envelope design based on local climate and economic conditions. Keywords: Artificial lighting, Consistent daily light integral, Energy modeling, Envelope design, Greenhouse, Life cycle cost analysis, Light emitting diode, Local agriculture.


2018 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
B. Kiss ◽  
ZS. Szalay

Building life cycle assessment is getting more and more attention within the topic of environmental impact caused by the built environment. Although more and more research focus on the embodied impact of buildings, the investigation of the operational energy use still needs attention. The majority of the building stock still does not comply with the nearly zero energy requirements. Also, in case of retrofitting, when most of the embodied impact is already spent on the existing structures (and so immutable), the importance of the operational energy rises. There are several methods to calculate the energy performance of buildings covering the range from simplified seasonal methods to detailed hourly energy simulations. Not only the accuracy of the calculations, but the computational time can be significantly different within the methods. The latter is especially important in case of optimization, when there is limited time to perform one calculation. Our research shows that the use of different calculation techniques can lead to different optima for environmental impacts in case of retrofitting. In this paper we compare these calculation methods with focus on computational time, accuracy and applicability to environmental optimization of buildings. We present the results in a case study of the retrofitting of a middle-sized apartment house in Hungary.


2019 ◽  
Vol 111 ◽  
pp. 03065
Author(s):  
Yiğit Yılmaz ◽  
Burcu Çiğdem Yılmaz

The importance of building energy performance has been substantially increasing in the last decades due to the global warming. Therefore, buildings within the existing stock and the new buildings are encouraged to achieve the energy performance restrictions and efficiency levels. In this context, a social housing archetype (Harct), which is constructed in each climate region of Turkey with a common design approach for temperate climate region, is evaluated as a base case to improve the energy performance for the cold climate region by the optimization of the life cycle cost (LCC). It is, namely, aimed to not only improve the energy performance of the archetype but also to ensure optimal cost efficiency as significant criterion. It is focused to optimize the façades of the Harct in terms of window width, and optic and thermo-physical properties of the façade with determining the efficient insulation thickness level for exterior walls and efficient glazing types for windows. Firstly, façade design is analysed to find out the minimum and maximum windows’ widths to achieve the optimal window sizes. Secondly, optic and thermo-physical properties and cost data of the opaque and transparent façade elements have been designated among the market products in accordance with the current regulations. Energy model of the building has been run by Energy Plus simulation tool, in order to integrate it with GenOpt for optimization. Optimization was performed to carry out efficient frontier cases. The results were evaluated from life cycle cost (LCC) and energy efficiency point of view to highlight the cost optimal point


2012 ◽  
Author(s):  
Jin How Ho ◽  
Azlan Abd. Rahman

Artikel ini membincangkan kajian ringkas berkaitan analisis kos kitaran hayat terhadap langkah-langkah pembaikan pengaratan bagi jambatan dan struktur marin konkrit yang terdedah kepada karbonasi atau serangan natrium klorida daripada air laut atau sumber-sumber lain. Perisian kos kitaran hayat, Bridge LCC 2.0 digunakan untuk menjalankan analisi kitaran hayat untuk tiga kes kajian melibatkan kaedah nilai bersih kini. Keputusan kajian menunjukkan analisis kos kitaran hayat berkeupayaan untuk membantu jurutera dan agensi pengangkutan dalam menilai keputusan penyelenggaraan yang efektif berkaitan dengan masalah pengaratan. Ia boleh digunakan sebagai alat analisis ekonomi kejuruteraan yang membantu mantaksir kos-kos perbezaan dan membuat pilihan terhadap langkah pembaikan pengaratan yang berkesan. Analisis kos kitaran hayat bagi langkah pembaikan dipengaruhi oleh banyak pemboleh ubah seperti kos permulaan, kos penyelenggaraan, tahun kekerapan, dan jangka masa analisis. Amalan terbaik untuk analisis kos kitaran hayat bukan sahaja mengambil kira perbelanjaan oleh agensi, tetapi perlu mempertimbangkan kos-kos oleh pengguna dan analisis sensitiviti di sepanjang jangka hayat sesuatu langkah pembaikan. Kata kunci: Analisis kos kitaran hayat, jambatan konkrit, pengaratan, langkah, pembaikan, pemulihan struktur, keberkesanan kos, kaedah nilai bersih kini (NPV) This paper discusses a short study on life cycle cost analysis (LCCA) on corrosion remedial measures for concrete bridges and marine structures, which are subjected to carbonation or ingress of sodium chloride from sea water and other sources. Life cycle costing software, Bridge LCC 2.0, was used to perform life cycle cost analyses on three case studies, based on net present value method. The analysis of the results showed that LCCA is capable of assisting engineers or transportation agencies to evaluate optimum maintenance decisions in corrosion–related problems. It can be used as an engineering economic analysis tool that helps in qualifying the differential costs and choosing the most cost–effective corrosion remedial measures. Life cycle costs for the remedial measures are influenced by many costing variables such as initial costs, periodic maintenance costs, frequency years and analysis period. The best practice of LCCA should not only consider agency expenditures but also user costs and sensitivity analysis throughout the service life of a remedial measure. Key words: Life cycle analysis, concrete bridges, corrosion, remedial measures, structural rehabilitation, cost-effective, net present value method (NPV)


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