Browsing by Author "Nasiri, Bahareh"

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Carbon sequestration potential of wooden residential buildings
(2024-06-11) Kumlin, Mikaela
Kemian tekniikan korkeakoulu | Master's thesis
This thesis investigates the carbon sequestration capacity of wooden residential buildings in the Uusimaa region of Finland. It emphasizes the need to optimize the lifetime of wooden buildings to maximize their ecological benefits. The study employs a generalized data analytical method, analysing the trends in construction and demolition of residential buildings in relation to population growth and GDP. The study concludes that using wood as a building material significantly reduces carbon footprints in the construction sector due to its carbon-sequestering properties. During the growth of trees used for wood, carbon dioxide is captured, aiding in the net reduction of atmospheric CO2 levels. The study also includes life comparisons between wooden buildings and those made from steel and concrete. The comparisons reveal that wooden buildings have lower carbon emissions throughout their lifecycle, and the greenhouse gases generated during the production and use of wood are significantly lower. The thesis discusses durability and fire safety in the context of modern innovations that enhance the resilience and longevity of wooden buildings. For example, modern fire-retardant treatments improve wooden structures' performance against high temperatures, addressing fire safety concerns. Policy recommendations include supporting the use of wood in residential buildings through incentives and stricter regulations on carbon emissions in the construction sector. The promotion of research and development in wood technology is also advocated. These policies aim to create an environment where wooden buildings become more prevalent, reducing the overall carbon footprint of urban areas. This highlights the potential of wooden buildings not only to lower carbon emissions but also to contribute to sustainable and resilient urban environments.
Estimating the material intensity of wooden residential houses in Finland
(2023-11) Nasiri, Bahareh; Kaasalainen, Tapio; Hughes, Mark
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Improving resource efficiency in the building sector is a significant challenge, largely due to a lack of knowledge about material usage in buildings. Material intensity (MI) quantifies materials used in buildings, normalized by floor area or volume. MIs serve as indices for material stock and flow models and as an inventory approach for assessing the environmental impact of the built environment. Therefore, this study aimed to determine MIs of Finnish wooden residential houses built between 1940 and 2010 due to the dominance of them in residential building stock and their demolition rates. Factors influencing MI and cross-country comparisons were also explored because they had not been explored enough in the literature. Results showed construction method, time cohort, floor area, design choices and footprint shape impacted MI. Accounting for variability of MI was recommended, particularly when using it for material stock and flow analysis. Data and method disparities restrict cross-country comparison of MI.
Estimating the material stock in wooden residential houses in Finland
(2021-11) Nasiri, Bahareh; Piccardo, Chiara; Hughes, Mark
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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.
Inventory of Timber in Finnish Residential Houses
(2022-11) Nasiri, Bahareh; Hughes, Mark
A4 Artikkeli konferenssijulkaisussa
To better understand the reuse and recycling potential of timber available within buildings, this paper creates an inventory of timber used in the construction of building typologies in Finland by analysing the technical documents of twenty typical houses and suggesting timber components that might be the best for reuse and recycling. The analysis showed that Finnish buildings contain timbers that could be reused and recycled. This highlights an opportunity and a need for the development of guidance on the principles and strategies for design for deconstruction and reuse. It was also determined that due to the design of these buildings, it is currently uneconomic to extract the timber components intact, even if they could be reused or repurposed. By making only minor changes to existing design, construction, and demolition practices, significant possibilities for reusing and recycling may be generated, adding value to timber, and reducing the demand for virgin wood.
Material inventory dataset for residential buildings in Finland
(2023-10) Kaasalainen, Tapio; Kolkwitz, Mario; Nasiri, Bahareh; Huuhka, Satu; Hughes, Mark
Data Article
This dataset contains the material volumes, masses, and intensities for a total of 45 residential building cohorts in Finland from the 1940s to the 2010s. The specific building types included are one dwelling houses and blocks of flats. The data were drawn from representative case buildings and their derivatives. The data are primarily based on construction drawings, complemented by other documents such as bills of materials. The source material was mainly obtained from the archives of the building inspection authority of the city of Vantaa, Finland. Material volumes were derived from the construction drawings either directly from annotations or, when needed, by further measurements made based on the same material. For minor lacks of information in the original documents, documents of similar buildings and literature were consulted. A total of 26 buildings were inventoried directly. For each included combination of building type, construction decade, and bearing material these were the ones with the most common façade material. In addition, 19 buildings with the second most common façade material were formed based on these to represent the 45 cohorts. Material masses, and by extension intensities, were calculated based on the recorded volumes and typical densities of construction materials used in Finland. The material volumes, masses, and intensities per material and in total are presented as three spreadsheet tables, along with a description sheet, on three corresponding hierarchical levels of aggregation: per representative building, per vertical building level (foundations, basement, first storey, etc.), and per building part (floor, exterior walls, interior walls, etc.). Furthermore, they are distinguished between the building structure and complementary building components (windows and doors). The data can be used in academic, policy related, and practical investigations of the building stock, such as in evaluating the material consumption consequences of different spatial planning strategies on various levels or estimating the materials embedded in the built environment and their potential for capitalisation in the circular economy.
Potential cascading of wood from the built environment in Finland
(2019-11-25) Nasiri, Bahareh
Kemian tekniikan korkeakoulu | Master's thesis
Construction and demolition waste is a concern today because many building components have a high intrinsic resource value, providing both an environmental and economic incentive for recycling and re-use. Of all building materials, wood is becoming an increasingly important resource, being both biotic and renewable. However, there are limits to how much can be sustainably harvested and, therefore, reuse (and recycling) of the material is vital. This is a priority in the EU and national regulations to develop empirical approaches for the efficient use of natural resources. Thus, the cascading concept becomes a declared goal of European policy as it concentrates on the efficient utilization of resources by using recovered wood in second-life applications. However, implementation of the cascading concept requires studies into when, where and in what quantity and quality the wood can be extracted from buildings. Therefore, the aim of this thesis was to investigate which building types have the highest share of wooden construction, and what quantity of wood is available in them. Further, a method was developed to determine when the wood elements could be cascaded. For this, a three-part methodology was developed to answer the aforementioned questions. Firstly, the building types comprising the higher share of wooden buildings by gross floor area (GFA) were identified through a funnel methodology. Their GFA was compared by gathering information regarding the wood used in buildings, and their overall GFA by intended use. Secondly, a wood stock analysis was applied to estimate the mass of wood in the buildings, by multiplying GFA and the wood intensity of building types constructed in different years. Thirdly, outflow analysis was developed to project the future demolition of wooden buildings, by GFA. The approach initially models the history of demolished GFA of buildings with the most likely reasons for demolition retrieved, then proposes future scenarios for the forecast of demolition by GFA. The study identified that in 2017, attached and detached houses accounted for the highest share of wooden buildings among all buildings. Overall, 85,64% of detached and attached houses by GFA comprise wooden buildings. The results also show that the aforementioned buildings contain 17, 50 megatons wood, highlighting the relevance of wood products in buildings and raising awareness of the cascading potential, and the importance of investigating the quality of, recovered wood. It also discusses the validity of the proposed outflow model as an alternative approach for forecasting the outflow of wood.
Properties of wood recovered from building demolition
(2024-08-29) Yin, Lili
Kemian tekniikan korkeakoulu | Master's thesis
The aim of this thesis is to find out if reclaimed wood material that has already been used as a structural element is strong enough to be used again as a structural element. Circular economy and 9R framework are discussed to give background to this topic as to why it is important to reuse wood and take some load off virgin materials. Wood properties and how wood ages are also discussed. For the experimental part, microscopy, 3-point bending, and contact angle tests were made. Microscopy was used to find out the species of the reclaimed wood and contact angle tests to analyse how ageing has affected the hygroscopicity. In 3-point bending tests, the MOE, MOR and failure strains were analysed. These obtained values were then compared with fresh wood material and with literature values. The obtained results of this case study will contribute to the larger pool of information that help with future practises of more sustainable nature.
Quality assessment of wood recovered from building demolition
(2024-01-23) Roy, Satyaki
Kemian tekniikan korkeakoulu | Master's thesis
Wood is an important resource for the construction of buildings and though renewable, has limited stocks in nature. The recycling and reuse of recovered wood has gained significant attention as society seeks sustainable solutions for waste management. Solutions related to better product design and optimized collection methods can help us recover wood from waste streams. However, one crucial aspect of this endeavour is the assessment of the quality of waste wood derived from building demolition, where large volumes of wood could be potentially recovered, and evaluating its suitability for reuse. This thesis aims to address the shortage of wood, by investigating the characteristics, conditions, and potential contaminants present in waste wood recovered from building demolition sites. Through a comprehensive assessment methodology, including physical and visual analyses, the quality of the waste wood will be evaluated. The study will focus on the reusability of recovered waste wood for construction, based on the available quality of wood recovered from the demolition sites. Furthermore, the economic feasibility of reusing waste wood will be examined to determine the suitability of reuse strategies from the recovered wood. The findings of this research will contribute to the development of best practices for material recovery from waste wood and its suitability for reuse. Ultimately, studies such as this thesis aim to promote the efficient utilization of waste wood resources, reduce waste genera-tion, and foster a more sustainable approach to building demolition waste man-agement.
Reusable Wood Structures in Finnish Detached Houses
(2020-05-04) Poikkeus, Onni
Kemiantekniikan korkeakoulu | Bachelor's thesis
The Use and Reuse of Modified Wood in Finnish Building
(2021-06-10) Lamminjoki, Leevi
Kemiantekniikan korkeakoulu | Bachelor's thesis