| 1. |
- Guasco, Martina, et al.
(author)
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Design optimization of a building attached sunspace through experimental monitoring and dynamic modelling
- 2020
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In: 12<sup>th</sup> Nordic Symposium on Building Physics (NSB 2020). E3S Web Conference. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- t. In Europe, buildings are responsible for 40% of the energy consumption and 36% of the CO2 emissions. Space heating largely contributes to these energy and climate impacts. Passive solar heating systems, as sunspaces, can contribute to increase solar heat gains, reducing space heating energy demand and the related use of fossil fuels. Careful design and local climatic considerations are essential to optimize the performance of sunspaces. In this study experimental field monitoring, dynamic modelling and steadystate methods are applied to analyse the thermal behaviour of an attached sunspace in an Italian existing building, as well as its potential contribution to the building’s energy balance. Design modifications for improved thermal performance of the sunspace are investigated. The results show overall agreement between the dynamic modellings and experimental monitoring of the sunspace and indicate that the sunspace’s indoor air temperature and hence solar energy gains are significantly increased with the design modifications, in contrast to the existing configuration. Maximum temperatures between 44 and 48 °C were observed for the existing and a modified alternative of the analysed sunspace. The dynamic simulation model and design modifications presented in this study can serve as basis for assessment and optimal configurations of sunspaces in their design stage.
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| 2. |
- Gustavsson, Leif, 1954-, et al.
(author)
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Cost Optimized Building Energy Retrofit Measures and Primary Energy Savings under Different Retrofitting Materials, Economic Scenarios, and Energy Supply
- 2022
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In: Energies. - : MDPI. - 1996-1073. ; 15:3
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Journal article (peer-reviewed)abstract
- We analyze conventional retrofit building materials, aluminum, rock, and glass wool materials and compared such materials with wood-based materials to understand the lifecycle primary energy implications of moving from non-renewable to wood-based materials. We calculate cost optimum retrofit measures for a multi-apartment building in a lifecycle perspective, and lifecycle primary energy savings of each optimized measure. The retrofit measures consist of the thermal improvement of windows with varied frame materials, as well as extra insulation of attic floor, basement walls, and external walls with varied insulation materials. The most renewable-based heat supply is from a bioenergy-based district heating (DH) system. We use the marginal cost difference method to calculate cost-optimized retrofit measures. The net present value of energy cost savings of each measure with a varied energy performance is calculated and then compared with the calculated retrofit cost to identify the cost optimum of each measure. In a sensitivity analysis, we analyze the cost optimum retrofit measures under different economic and DH supply scenarios. The retrofit costs and primary energy savings vary somewhat between non-renewable and wood-based retrofit measures but do not influence the cost optimum levels significantly, as the economic parameters do. The lifecycle primary use of wood fiber insulation is about 76% and 80% less than for glass wool and rock wool, respectively. A small-scale DH system gives higher primary energy and cost savings compared to larger DH systems. The optimum final energy savings, in one of the economic scenarios, are close to meeting the requirements in one of the Swedish passive house standards.
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| 3. |
- Nasiri, Bahareh, et al.
(author)
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Estimating the material stock in wooden residential houses in Finland
- 2021
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In: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 135, s. 318-326
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Journal article (peer-reviewed)abstract
- The aims of this study were to quantify the amount of wood in residential houses in Finland in 2017 that could be available for cascading, and to characterize the age distribution and gross floor area of the houses in the stock. Through a bottom-up material stock analysis, the mass of wood and the gross floor area of buildings in each building type and construction period were estimated. The study found that 10 million tons of wood are contained in the structures of residential houses built before 1969, equivalent to around 59% of the stock. Since much of this stock is nearing end of life, this material should soon become available for cascading so providing a significant potential resource. It was also found that, overall, the structural parts of residential houses embody 17.5 million tons of wood, of which around 9 million tons is, theoretically, reusable and recyclable. However, for effective reuse and recycling, further analysis of the quality, type and future availability of recovered wood is required. The current results could be used for material stock and flow analyses to help planning for the use of recovered wood. Further research is needed to fill in gaps in the time-series of the number and gross floor area of buildings constructed and their average gross floor area. Moreover, a material intensity analysis of Finnish buildings is needed to better quantify the wood used.
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| 4. |
- Piccardo, Chiara, et al.
(author)
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Challenge-based, interdisciplinary learning for sustainability in doctoral education
- 2022
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In: International Journal of Sustainability in Higher Education. - 1467-6370. ; 23:7, s. 1482-1503
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Journal article (peer-reviewed)abstract
- Purpose: Doctoral candidates possess specialized knowledge that could support sustainability transitions. Doctoral education, however, often focusses on discipline-specific topics and working methods, making it difficult to “see the bigger picture”. This summer school on wood construction gathered doctoral candidates from different fields to explore how solutions to complex sustainability issues could be found by working together across disciplines and by engaging multiple stakeholders. The purpose of this study is to report the pedagogical approaches taken and to understand whether these fostered the candidates’ ability to develop systemic solutions and professional competency. Design/methodology/approach: Twenty doctoral candidates from various backgrounds participated in a two-week summer school organized by a consortium of four universities. Interdisciplinary groups worked on real-life challenges using a systemic approach to co-create tangible solutions. To support the creation of socio-technical innovations, stakeholders and experts from different fields were involved. The participants completed two questionnaires during the summer school to help elucidate their learning experiences. Findings: The doctoral candidates showed strong willingness to cooperate across disciplines, though they found it important to connect this learning experience to their research. The candidates reported that the experience enhanced their ability to work in a multidisciplinary capacity. The experience identified a solid basis for interdisciplinary learning principles that could be replicated. Originality/value: The summer school focussed on an innovative learning experience based on a systems thinking approach and the development of interdisciplinary capacity in the research-business ecosystem.
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| 5. |
- Piccardo, Chiara, et al.
(author)
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Comparative Life-Cycle Analysis of Building Materials for the Thermal Upgrade of an Existing Building
- 2019
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In: SBE19 Brussels - BAMB-CIRCPATH "Buildings as Material Banks - A Pathway For A Circular Future"5–7 February 2019, Brussels, Belgium. - : IOP Publishing.
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Conference paper (peer-reviewed)abstract
- The existing building stock is estimated to need major renovations in the near future. At the same time, the EU energy-efficiency strategy entails upgrading the energy performance of renovated buildings to meet the nearly-zero energy standard. To upgrade existing buildings, two main groups of measures can be adopted: thermally-improved building envelope and energy-efficient technical devices. The first measure usually involves additional building materials for thermal insulation and new building cladding, as well as new windows and doors. A number of commercially-available materials can be used to renovate thermal building envelopes. This study compares the life-cycle primary energy use and CO2 emission when renovating an existing building using different materials, commonly used in renovated buildings. A Swedish building constructed in 1972 is used as a case-study building. The building's envelope is assumed to be renovated to meet the Swedish passive house standard. The entire life cycle of the building envelope renovation is taken into account. The results show that the selection of building materials can significantly reduce the production primary energy and associated CO2 emissions by up to 62% and 77%, respectively. The results suggest that a careful material choice can significantly contribute to reduce primary energy use and CO2 emissions associated with energy renovation of buildings, especially when renewable-based materials are used.
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| 6. |
- Piccardo, Chiara, et al.
(author)
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Deep energy retrofits using different retrofit materials under different energy scenarios : life cycle cost and primary energy implications
- 2022
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In: Digital proceedings of the 5th South East European Conference on Sustainable Development of Energy, Water and Environment System. - : International center for sustainable development of energy, water och environment systems (SDEWES).
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Conference paper (peer-reviewed)abstract
- Building renovation is considered a key strategy to facilitating the transition towards a renewable energy system, mitigating climate change and addressing energy poverty. However, the rate of buildings undergoing deep energy retrofit in Europe is below 1% per year. The study analyses the life cycle cost and primary energy impacts to retrofit a residential building to an annual final energy use of 50 and 30 kWh/m2, respectively, corresponding to two Swedish passive house standards. The retrofit includes the thermal improvement of the building envelope, and the increased efficiency of water taps and ventilation system. We assume the use of different retrofit materials. The study also analyses the effects of various energy scenarios for district heating and electricity on the primary energy savings and costs of the building retrofit. Finally, we compare the economic net present value (NPV) of the net primary energy savings due to the retrofit options and the cost of them. Retrofit to 50 kWh/m2 is cost efficient while the 30 kWh/m2 level is close to be cost efficient for higher biomass prices. The primary energy use to produce the retrofit options is much smaller in all cases than the operation primary energy savings of them. The cost of different retrofit material versions is similar while the production primary energy use is much lower for wood based materials. Different electricity production scenarios affect the net primary energy savings but are marginal in terms of costs.
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| 7. |
- Piccardo, Chiara, et al.
(author)
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Energy and carbon balance of materials used in a building envelope renovation
- 2019
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In: SBE19 Brussels - BAMB-CIRCPATH "Buildings as Material Banks - A Pathway For A Circular Future"5–7 February 2019, Brussels, Belgium. - : IOP Publishing.
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Conference paper (peer-reviewed)abstract
- Construction and demolition waste (CDW) are a priority waste stream in EU's polices, accounting for about 30% of all waste generated. At the same time, according to the EU energy-efficiency directive, existing buildings subject to significant renovation need to be upgraded in their thermal building envelope in order to meet higher energy performance standard. This involves additional building materials and hence increases the CDW generation. This study investigates the energy and CO2 emission balance of building envelope renovation when using different building materials, taking into account the production and end-of-life stages. The study is based on a Swedish case-study building assumed to be upgraded to the passive house standard. Benefits from waste recovering are considered, including construction and demolition wastes. The results show that the selection of building materials can significantly affect the primary energy and CO2 emission balances. Depending on the material alternative the end-of-life primary energy use and net CO2 emission can be reduced by 5%-21% and 2%-24%, respectively, compared to the initial primary energy use and net CO2 emission. Therefore, a careful material choice at the design stage, as well as an efficient waste management, can contribute to reduce primary energy use and CO2 emission associated with energy renovation of existing buildings.
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| 8. |
- Piccardo, Chiara, et al.
(author)
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Implications of different modelling choices in primary energy and carbon emission analysis of buildings
- 2021
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In: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 247
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Journal article (peer-reviewed)abstract
- In recent years, several comparative life cycle analyses have shown that increasing the use of wood in buildings can reduce the life cycle primary energy use and carbon emission of buildings. This study reviews the life cycle inventory methodology of primary energy use and carbon emissions, based on ecoinvent database, considering different modelling choices for (i) materials heating values; (ii) biogenic carbon; (iii) calcination and carbonation processes; (iv) electricity production scenarios; (v) impact distribution of multi-functional processes; (vi) post-use benefits. The analysis relates to the standards while the implication of different modelling choice is shown by comparing the primary energy use and carbon emission in the production and end-of-life stages of a multi-storey residential building with concrete, cross laminated timber and modular timber structures, respectively. The results highlight the displacement between different modelling choices in terms of primary energy use and carbon emissions. Such modelling options especially influence the LCA results in the product stage and beyond the end of life stage, and especially wood- and/or cement-based materials.
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| 9. |
- Piccardo, Chiara, et al.
(author)
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Life cycle cost and primary energy analysis of a multi-storey residential building retrofit to different energy levels with varied materials
- 2020
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In: Book of Abstracts: 6th International Conference on Smart Energy Systems. - Aalborg : Aalborg university. ; , s. 127-127
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Conference paper (peer-reviewed)abstract
- The study analyses the life cycle cost efficiency and primary energy use to retrofit a multi-storey residential building to an annual final energy use of 50 and 30 kWh per heated floor area, respectively, corresponding to two Swedish passive house standards. We compare the net present value (NPV) of the net primary energy savings of the retrofitting options and the cost of them. The retrofit includes additional insulation to basement walls, exterior walls, and attic floor, new windows, efficient water taps and ventilation heat recovery. We assume the use of different building materials, including glass wool, rock wool and wood fibre for thermal insulation, and aluminium, brick and wood for cladding. We also analyse the effects of various energy scenarios on the primary energy savings and costs of the building retrofit. The heat supply is from bio-based or electric heat pump district heating. The electricity is from standalone fossil gas (100%) or bio (30%) and wind electricity (70%) plants. The biomass cost is based on current or 60% higher prices. Retrofit to 50 kWh per heated floor area is cost efficient while the 30 kWh level is close to be cost efficient for higher biomass prices. The primary energy use to produce the retrofit options is much smaller in all cases than the operation primary energy savings of them. The cost for different retrofitting material options is rather similar while the production primary energy use is much lower for wood based materials.
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| 10. |
- Piccardo, Chiara, et al.
(author)
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Retrofitting a building to passive house level : A life cycle carbon balance
- 2020
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In: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 223, s. 1-13
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Journal article (peer-reviewed)abstract
- The building sector is one of the major contributors to global carbon emission. Energy retrofit of existing buildings reduces CO2-eq emission in the operation phase but typically entails further emissions from the production, maintenance and disposal of the materials used for the retrofitting (non-operation CO2-eq emission). This study analyses the life cycle carbon balance of a building retrofitted to passive house level, considering two alternative standards applicable in Sweden. The study considers the implications of using different building materials for thermal insulation, building façade and windows of the retrofitted building. It also considers different electricity production scenarios, assuming standalone production with fossil coal, fossil gas, and a mix of wind and biomass. Our results show that the operation CO2-eq emission decreases by between 50 and 82% in the retrofitted building depending on the passive house standard, with minor deviations between the electricity scenarios. The non-operation CO2-eq emission accounts for between 4 and 25% of the operation CO2-eq savings depending on the passive house standard and material option. Deviations between material options are increasingly reduced when assuming fossil gas and wind/biomass for electricity production instead of fossil coal. A careful selection of materials can reduce the net CO2-eq savings by up to 68%, especially when using wood material.
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