| 1. |
- Bhattacharjee, Shimantika, et al.
(författare)
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Energy and indoor thermal performance analysis of a glazed façade high-rise building under various Nordic climatic conditions
- 2023
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Ingår i: Energy Reports. - : Elsevier. - 2352-4847. ; 10, s. 3039-3053
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Tidskriftsartikel (refereegranskat)abstract
- Research has shown that glazed buildings can have higher energy use and are more prone to overheating than other types of buildings. However, few studies have explored the performance of glazed buildings in cold climates. This article aims to evaluate the energy and indoor thermal performance of a high-rise residential building with glazed façades and balconies under Nordic climatic conditions, through a parametric study. Dynamic, whole-year simulations are used to evaluate the impact of four design parameters (with and without glazed balconies, type of balcony glazing, window to wall ratio, and building location within the Nordic region) on the energy and indoor thermal performance of the building. The results show that the building without glazed balconies outperformed that with glazed balconies. Changing from single- to double-pane glazing also helped to reduce energy use and overheating, as did lowering the window-to-wall ratio. Overheating of apartments was found to occur during the summer in five of the six locations simulated, which suggests that solar control strategies might be needed for glazed buildings even in a Nordic climate. This study highlights the importance of further research on glazed residential buildings, which are becoming more common in contexts subject to such climates.
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| 2. |
- Bhattacharjee, Shimantika
(författare)
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Energy efficiency strategies for residential buildings in a subarctic climate: Impacts on energy use and indoor thermal climate
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Adopting energy efficiency strategies in residential buildings are beneficial as these not only improve the energy performance but also improves the indoor thermal climate and minimizes the greenhouse gas emissions. There exist numerous studies on energy efficiency strategies and their influence on indoor thermal climate in residential buildings in cold climates. However, there is a lack of documented and systematic studies that explicitly investigated the selection of appropriate energy efficiency strategies and their impact on the indoor thermal climate in residential buildings in a subarctic climate. Moreover, the impact of such energy efficiency strategies on the life cycle energy use of buildings has not been given appropriate attention in the existing literature. Due to the extreme climate conditions in a subarctic climate – severe cold and dark winter with heavy snow and mild short summer – buildings require a considerable amount of heating energy to maintain a comfortable temperature indoors. Therefore, it is important to adopt energy efficiency strategies that can help obtain operational and life cycle energy savings along with a better indoor thermal climate.The aim of this study is to evaluate the impact of different energy efficiency strategies on energy use and thermal indoor climate of three selected case study residential buildings in a subarctic climate. Three research questions were formulated: (1) What is the impact of evaluated energy‐efficiency strategies on the operational energy use?, (2) What is the impact of evaluated energy‐efficiency strategies on the life‐cycle energy use?, and (3) What is the impact of evaluated energy‐efficiency strategies on the thermal indoor climate? To address research questions 1 and 3, implemented energy‐efficiency strategies in two low‐energy buildings were evaluated using measured energy data and dynamic building energy and indoor climate simulations. To address research question 2, different combinations of energy efficiency strategies were explored using a multiobjective optimization method to identify optimal retrofitting solutions in terms of life cycle energy savings for a 1980s building.Results show that besides an airtight and highly insulated building envelope, a well‐functioning heating system is important to achieve low operational energy use. Findings highlight that the role of occupants is vital both in regard to the proper functioning of the heating system and to reduce the need for active heating in an airtight and highly insulated building. The occupants are also important in terms of maintaining a comfortable indoor thermal climate, especially during summer since manual airing and shading can help moderate temperatures indoors. Furthermore, findings show that applying glazed balconies is not necessarily a favorable strategy in terms of operational energy use and indoor thermal climate for a building in a subarctic climate. In comparison, using double instead of single pane balcony glazing and lowering the window to wall ratio improved the operational energy and indoor thermal climate performance. A combination of energy efficiency strategies including the addition of insulation on walls and roofs, there placement of windows from double pane to triple pane ones and the installation of heat recovery ventilation were found optimal to achieve considerable savings in both operational and life cycle energy use. In many cases, the fundamental aim of adopting energy efficiency strategies is to reduce operational energy use, while impacts on life cycle energy use and indoor thermal climate are less prioritized. The findings illustrate the importance of considering impacts on operational energy use, life cycle energy use and indoor thermal climate simultaneously to select energy efficiency strategies that ensure a better and more sustainable built environment.
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| 3. |
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| 4. |
- Lidelöw, Sofia, et al.
(författare)
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The promise of BIM? Searching for realized benefits in the Nordic architecture, engineering, construction, and operation industries
- 2023
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Ingår i: Journal of Building Engineering. - : Elsevier. - 2352-7102. ; 76
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Tidskriftsartikel (refereegranskat)abstract
- Benefits of BIM are not being achieved as expected in the mainstream architecture, engineering, construction, and operation (AECO) industries. Here, we aim to contrast expected and realized BIM benefits in AECO companies and discuss explanations for why benefits proposed in literature have, or have not, been realized. A qualitative research approach is applied to collect and analyse interview data from 47 companies in Finland, Norway and Sweden. Findings show that realized benefits typically occur “within the current practice” of individual organizations' project-related work. In contrast, expected but not realized benefits are long-term, lifecycle oriented and challenge current business and practice. Our proposed explanations acknowledge that fully realizing the expected benefits of BIM suggested in the technology-driven research is restrained by the current sector state-of-practice and assumes a high degree of BIM maturity among all cooperating companies. Thus, we discuss how explanations relate to the fundamental change required to radically leverage the benefits of BIM, challenging both current ways of work and the ubiquitous assumption of clients as drivers for BIM implementation in the sector. Based on our research, we argue that client demand is insufficient to realize the promise of BIM. Suggested research implications include a need for greater supply-driven logic among suppliers of BIM expert services, and the integration of multi-disciplinary competencies within and beyond the traditional disciplines. The research demonstrates the gap between state-of-the-art BIM predicted in literature and mainstream industry's adoption and highlights the importance of extending BIM research to better account for socio-organizational and process aspects of benefits and adoption.
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| 5. |
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| 6. |
- Schade, Jutta, et al.
(författare)
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The thermal performance of a green roof on a highly insulated building in a sub-arctic climate
- 2021
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 241
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Tidskriftsartikel (refereegranskat)abstract
- Green roofs are complex systems, with a vegetation layer covering the outermost surface of the building shell. An effective design may confer environmental and energy benefits. Most field studies evaluating green roof performance have been conducted in warmer climates with few studies of full-scale green roofs in cold regions. No study has so far evaluated the energy performance of a green roof in a sub-arctic climate. This study demonstrates the heat flow and thermal effect of an extensive green roof versus a black bare roof area on a highly insulated building in the sub-arctic town of Kiruna, Sweden, for the period from November 2016 to February 2018. Measured temperature and heat flux values were consistently higher and more variable for the black roof than the green roof, except during the snow-covered winter months when the responses were similar. The cumulative heat flux showed that the net heat loss was greater through the black than the green roof, but the values remained low. Overall, the study confirms that the energy benefit of a green roof on a highly insulated building in a subarctic climate is low.
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| 7. |
- Shadram, Farshid, 1987-, et al.
(författare)
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Exploring the trade-off in life cycle energy of building retrofit through optimization
- 2020
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- Building retrofit is considered as a vital step to achieve energy and climate goals in both Europe and Sweden. Nevertheless, retrofitting solutions based merely on reducing operational energy use can increase embodied energy use, mainly due to altering the existing trade-off between the two. Considering this trade-off is vitally important, especially for retrofitting buildings located in cold climate regions, as reduction of operational energy use to meet standards of energy-efficient buildings may require a deep retrofitting that can considerably increase the embodied energy and thus be unfavorable from a Life Cycle Energy (LCE) perspective. This article presents a case study in which multi-objective optimization was used to explore the impact of a wide range of retrofitting measures on the aforementioned trade-off for a building in Sweden located in a subarctic climatic zone. The studied building was a typical 1980s multi-family residence. The goal was to explore and compare the optimal retrofitting solution(s) for the building, aiming to achieve Swedish energy-efficient building standards (i.e. new-build and near-zero energy standards). The results of the optimization indicated that (1) use of additional insulation in walls and roof, (2) replacement of existing windows with more energy-efficient ones, and (3) change of traditional mechanical extract ventilation to heat recovery ventilation are the primary and optimal retrofitting measures to fulfill the new-build Swedish energy standard and achieve highest LCE savings. However, to fulfill more far-reaching operational energy savings, application of additional retrofitting measures was required, increasing the embodied energy use considerably and resulting in lower LCE savings compared to the optimal retrofitting solution that only reached the Swedish new-build energy standard. The LCE difference between the optimal retrofitting solutions that fulfilled the new-build standard and the strictest near-zero (passive house) standard was 1862 GJ, which is equivalent to almost four years of operational energy use for the original building. This indicates that there is a limit to the reduction of operational energy use when retrofitting existing buildings, beyond which additional reductions can considerably increase the embodied energy and thus be unfavorable in terms of LCE use.
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| 8. |
- Sällström Eriksson, Liza, et al.
(författare)
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Maintaining or replacing a building's windows: a comparative life cycle study
- 2024
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Ingår i: International Journal of Building Pathology and Adaptation. - : Emerald Publishing. - 2398-4708 .- 2398-4716.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Energy-efficiency measures have always been important when renovating aging building stock. For property owners, window intervention is a recurring issue. Replacement is common to reduce operational heating energy (OHE) use, something many previous building renovation studies have considered. Maintaining rather than replacing windows has received less attention, especially for multi-residential buildings in a subarctic climate where there is great potential for OHE savings. The objective was to assess the life cycle (LC) climate impact and costs of three window maintenance and replacement options for a 1980s multi-residential building in subarctic Sweden.Design/methodology/approach: The options’ embodied and operational impacts from material production, transportation and space heating were assessed using a life cycle assessment (LCA) focusing on global warming potential (LCA-GWP) and life cycle costing (LCC) with a 60-year reference study period. A sensitivity analysis was used to explore the impact of uncertain parameters on LCA-GWP and LCC outcomes.Findings: Maintaining instead of replacing windows minimized LC climate impact and costs, except under a few specific conditions. The reduced OHE use from window replacement had a larger compensating effect on embodied global warming potential (E-GWP) than investment costs, i.e. replacement was primarily motivated from a LC climate perspective. The LCA-GWP results were more sensitive to changes in some uncertain parameters, while the LCC results were more robust.Originality/value: The findings highlight the benefits of maintenance over replacement to reduce costs and decarbonize window interventions, challenging property owners’ preference to replace windows and emphasizing the significance of including maintenance activities in future renovation research.
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| 9. |
- Törnå, Niklas, et al.
(författare)
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A coordination perspective on dialogue processes between planners and developers in a sustainable urban development project
- 2020
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Ingår i: WSBE 20 - World Sustainable Built Environment - Beyond2020 2-4 November 2020, Gothenburg, Sweden. - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- Several of Sweden's Local Planning Authorities (LPAs) use developer dialogue processes between them and building actors to aid in the implementation of urban development projects. The idea is often to achieve ambitious local sustainability and to encourage a generally appreciated collaborative culture; however, processes of planners/developers interactions are challenging to manage in practice. In this study, we aim to depict and analyse a developer dialogue process used by a Swedish LPA in an on-going sustainable urban development project through the theoretical lens of organizational coordination mechanisms. Particular focus is placed on exploring how planners and develops interact while negotiating and implementing locally defined sustainability priorities. Empirical material was collected through document analysis, workshops and interviews with LPA representatives. Findings from the ongoing study indicates that the LPA manage a mixture of formal and informal interdependencies throughout in an attempt to achieve a greater fulfilment of their sustainability goals, and better outcomes in terms of product compliance. Furthermore, the use of coordination mechanisms for analysing the project seems to represent an important instrumental knowledge gap for better understanding sustainable urban development projects' implementation and outcomes.
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