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- Khadra, Alaa, et al.
(författare)
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Development of a Weight Factor Method for Sustainability Decisions in Building Renovation : Case Study Using Renobuild
- 2020
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 12:17
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Tidskriftsartikel (refereegranskat)abstract
- Energy efficiency investments have become strategically important for the European Union. In particular, energy efficient renovation and investment in the existing building stock have become major challenges. Renovation of a building should involve a holistic and integrated design process, which considers all aspects of sustainability. The aim of this work is to suggest a mathematical model that weighs economic, social and ecological aspects into a measure that supports housing owners/decision makers to find the optimal renovation alternative from their perspective, taking factors such as budget, energy consumption, etc. into consideration. Multi-criteria decision-making (MCDM) concerns structuring and solving multiple-criteria decision problems. MCDM has become popular in energy planning as it enables the decision maker to pay attention to all the criteria available and make the appropriate decision as per the priority of the criteria. In this study, the concept is introduced based on economic, social and ecological aspects assessed during a renovation project. A pedagogical example illustrates the suggested numerical system for comparing different renovation alternatives. The suggested method will facilitate decision-making processes in renovation projects and will allow decision makers to choose the best renovation alternatives that are in line with their business ideas and principles.
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| 2. |
- Khadra, Alaa, et al.
(författare)
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Economic performance assessment of three renovated multi-family buildings with different HVAC systems
- 2020
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 224
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Forskningsöversikt (refereegranskat)abstract
- The EU has adopted several policies to improve energy efficiency. One of these policies aims to achieve energy efficient renovations in at least 3% annually of buildings in EU. The aim of this study was to provide an accurate economic comparison between three similar multi-family buildings that have undergone the same energy efficiency measures, with essential differences regarding the installed ventilation systems. The selected ventilation systems were: 1) balanced mechanical ventilation with heat recovery; 2) exhaust ventilation with air pressure control; and 3) exhaust ventilation with an exhaust air heat pump. In the latter two cases, radiators pre-heat supply air. Life cycle cost analysis were conducted using real investment and operational costs for the three buildings. Sensitivity analysis was also made for different discount rates and energy price escalation patterns. It was found that the building with exhaust ventilation has the lowest life cycle cost. At 2% inflation rate, 3% real discount rate and 1% real energy price escalation, the building with exhaust air heat pump and the building with mechanical ventilation with heat recovery has 13% and 29% higher life cycle cost than the building with exhaust ventilation, respectively. The sensitivity analysis further showed that a lower discount rate gives higher future costs and gives more profitability of systems with heat recovery with lower future costs. Energy price assumptions have a crucial impact on the results and change the profitability of studied renovation packages.
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| 3. |
- Myhren, Jonn Are, 1979-, et al.
(författare)
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The perception of Swedish housing owner’s on the strategies to increase the rate of energy efficient refurbishment of multi-family buildings
- 2020
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Ingår i: Intelligent Buildings International. - : Informa UK Limited. - 1750-8975 .- 1756-6932. ; 12:3, s. 153-168
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Tidskriftsartikel (refereegranskat)abstract
- Improving the energy performance of existing buildings is crucial for reaching both EU and national climate and energy targets. The main objective of this study was to map challenges that Swedish housing owners perceive when making energy-efficiency refurbishments. A secondary objective was to compare how well these challenges relate to national strategies. The study applied a combined methods approach with audience response meters and in-depth qualitative semi-structured interviews. The housing owners express the view that they have sufficient knowledge of national ambitions to improve the energy performance of buildings and welcome the new building regulations. Despite this supposed knowledge and the current economic situation with beneficial loans, the refurbishment rate still remains low. The housing owners explain that they are concerned about the ‘performance gap’ and request more accurate energy performance predictions. They are also waiting for proof that all sustainability goals can be reached in reality. Probably, too few projects fulfilling ambitions in all categories: economically, socially and energy-wise have been followed up and demonstrated nationally. The new national information centre on refurbishment of buildings may help to spread information about such projects, raise awareness and thus increase the refurbishment rate.
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