Aaltodoc Repository :: Browsing by Author "Amiri, Ali"

Browsing by Author "Amiri, Ali"

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Are LEED-certified buildings energy-efficient in practice?
(MDPI AG, 2019-03-20) Amiri, Ali; Ottelin, Juudit; Sorvari, Jaana; Department of Built Environment; Water and Environmental Eng.; Real Estate
Depletion of natural resources and climate change are undoubtedly the biggest challenges that humankind faces today. Here, buildings have a crucial role since they consume the majority, i.e., 30% to 40% of the total energy resources. Green building certification is one of the solutions to limit the energy use in buildings. In addition, it is seen to indicate a consideration for sustainability aspects in construction. LEED is the most widely used certificate worldwide. However, recently some critics have raised doubts about LEED and whether it actually implies sustainability. Most of the criticism has been targeted to the energy aspects of LEED. Nevertheless, there is no consensus on the usefulness of LEED: is it really beneficial for the environment, and is it worth of the money and time invested on the certification process? In this study a critical analysis of the literature to find an answer to this question is presented. Altogether 44 peer reviewed articles dealing with the abovementioned issue were selected out of 164 search result. Based on the studied material, the different aspects of LEED from the viewpoint of energy-efficiency are discussed. From the 44 reviewed articles, ten articles state that LEED certificate indicates energy efficiency while eight papers end up with an opposite conclusion. The rest of the papers do not take any stand on this matter. The study showed that energy efficiency of LEED-certified buildings is questionable especially at lower levels, i.e., certified. Therefore, it is recommended to modify the Energy and Atmosphere category of LEED in order to improve the actual energy performance of buildings.
Can future cities grow a carbon storage equal to forests?
(IOP Publishing Ltd., 2023-04-01) Talvitie, Ilmari; Kinnunen, Antti; Amiri, Ali; Junnila, Seppo; Department of Built Environment; Real Estate
Urban areas have experienced exponential growth since the industrial revolution and by virtue, the urban population has followed. Current projections suggest that this growth has yet to reach its peak implying that urban developments will continue to sprawl into untouched territories. This growth and subsequent sprawl will undoubtedly come at the expense of forested areas. This study presents a carbon storage factor indicator for new urban developments. It is a novel concept which integrates urban planning, land use changes and wooden construction. The factor sets a carbon storage requirement for new urban areas that are developed at the expense of forested areas. The study is conducted in four parts. First, we estimate the carbon storage potential of forest areas via existing literature and databases. Then we collect all new development and construction estimates up to the year 2050 for the whole metropolitan region in Finland. Next, we conduct scenario analyzes for different demand levels of wood in projected residential developments. Finally, we compare the carbon storage potential of the future building stock to the forest areas planned for development. The data used is provided by the regional authority. The results detail that the future residential building stock can store between 128-733 kt of carbon. The lower level implies that current construction methods can only partially preserve the carbon storage of an area in buildings. However, the higher level suggests future buildings to be able to exceed the carbon storage potential of forest areas by nearly 47 tC ha−1. The study reminds that an increased use of wood is dependent on sustainable forest management practices. Furthermore, it is not our purpose to promote urban development into entirely new areas but rather encourage urban planners to consider the carbon balance when it is the only viable option.
Cities as carbon sinks - Classification of wooden buildings
(IOP Publishing, 2020-08-28) Amiri, Ali; Ottelin, Juudit; Sorvari, Jaana; Junnila, Seppo; Department of Built Environment; Real Estate
Although buildings produce a third of greenhouse gas emissions, it has been suggested that they might be one of the most cost-effective climate change mitigation solutions. Among building materials, wood not only produces fewer emissions according to life-cycle assessment but can also store carbon. This study aims to estimate the carbon storage potential of new European buildings between 2020 and 2040. While studies on this issue exist, they mainly present rough estimations or are based on a small number of case studies. To ensure a reliable estimation, 50 different case buildings were selected and reviewed. The carbon storage per m2 of each case building was calculated and three types of wooden buildings were identified based on their carbon storage capacity. Finally, four European construction scenarios were generated based on the percentage of buildings constructed from wood and the type of wooden buildings. The annual captured CO2 varied between 1 and 55 Mt, which is equivalent to between 1% and 47% of CO2 emissions from the cement industry in Europe. This study finds that the carbon storage capacity of buildings is not significantly influenced by the type of building, the type of wood or the size of the building but rather by the number and the volume of wooden elements used in the structural and non-structural components of the building. It is recommended that policymakers aiming for carbon-neutral construction focus on the number of wooden elements in buildings rather than more general indicators, such as the amount of wood construction, or even detailed indirect indicators, such as building type, wood type or building size. A practical scenario is proposed for use by European decision-makers, and the role of wood in green building certification is discussed.
Comparative carbon footprint analysis of residents of wooden and non-wooden houses in Finland
(IOP Publishing, 2021-07) Ottelin, Juudit; Amiri, Ali; Steubing, Bernhard; Junnila, Seppo; Department of Built Environment; Real Estate; Leiden University
Sustainable forest management and harvested wood products together can create a growing carbon sink by storing carbon in long-lived products. The role of wood products in climate change mitigation has been studied from several perspectives, but not yet from a consumer's view. In this study, we examine the impact of wooden housing on consumer carbon footprints in Finland. We use the 2016 Finnish Household Budget Survey and Exiobase 2015, a global multi-regional input-output model. The sample size is 3700 households, of which 45% live in a wooden house. We find that residents of wooden houses have a 12(+/- 3)% (950 kg CO2-eq/year) lower carbon footprint on average than residents of non-wooden houses, when income, household type, education of the main income provider, age of the house, owner-occupancy and urban zone are controlled in regression analysis. This is not fully explained by the impact of the construction material, which suggests that the residents of wooden houses may have some features in their lifestyles that lower their carbon footprints further. In addition, we find that an investment in a new wooden house in an urban area has a strong reducing impact on a consumer's carbon footprint, while investments in other types of housing have a weaker or no reducing impact. Our findings support wooden housing as a meaningful sustainable consumption choice.
Economic and technical considerations in pursuing green building certification : A case study from Iran
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-01-19) Amiri, Ali; Ottelin, Juudit; Sorvari, Jaana; Junnila, Seppo; Department of Built Environment; Real Estate; Water and Environmental Eng.
Buildings use 30-40% of all energy resources and are thus the main consumers in modern society. Moreover, buildings require a vast amount of different raw materials. During the last two decades, several green building certifications have been created in order to consider the social, economic, and environmental aspects of the sustainability of buildings. One of the most famous and widely used of these certifications is Leadership in Energy and Environmental Design (LEED). So far, the use of LEED has concentrated in the US and other developed countries. One reason that restricts the use of this point-based system certification in developing countries is the limited data about its costs. In this study, the extra cost of the certification process were evaluated, besides the changes needed in the design of the building to reach the points required by LEED. At the first stage, the number of points the case study earns in its current format (Scenario 1) were assessed, then the cost difference of getting either the Certified (Scenario 2) or Silver (Scenario 3) level LEED certification for the building was studied. It was found that besides some technical considerations, filling the criteria of the Certified and Silver level increases the total costs of construction by 3.4% and 5.9%, respectively. Further improvement of the building's energy efficiency would enable the attainment of a higher-level certification. The results of the study could help to promote the use of green building certifications inWestern Asia.
Embodied emissions of buildings - A forgotten factor in green building certificates
(Elsevier Science, 2021-06-15) Amiri, Ali; Emami, Nargessadat; Ottelin, Juudit; Sorvari, Jaana; Marteinsson, Björn; Heinonen, Jukka; Junnila, Seppo; Department of Built Environment; Real Estate; University of Iceland; Finnish Environment Institute
The construction and use of buildings consume a significant proportion of global energy and natural resources. Leadership in Energy and Environmental Design (LEED) is arguably the most international green building certification system and attempts to take actions to limit energy use of buildings and construct them sustainably. While there has been a wide range of research mainly focused on energy use and emission production during the operation phase of LEED-certified buildings, research on embodied emissions is rare. The aim of this study is to evaluate the efficiency of LEED regarding initial (pre-use) embodied emissions using life cycle assessment (LCA). The study comprised several steps using a designed model. In the first step, three optional building material scenarios were defined (optimized concrete, hybrid concrete-wood, and wooden buildings) in addition to the base case concrete building located in Iceland. Second, an LCA was conducted for each scenario. Finally, the number of LEED points and the level of LEED certification was assessed for all studied scenarios. In addition, a comparison regarding embodied emissions consideration between LEED and Building Research Establishment Environmental Assessment Method (BREEAM) as mostly used green certificate was conducted in the discussion section. The LCA showed the lowest environmental impact for the wooden building followed by the hybrid concrete wood building. In the LEED framework, wooden and hybrid scenarios obtained 14 and 8 points that were related to material selection. Among these points, only 3 (out of a total of 110 available points) were directly accredited to embodied emissions. The study recommends that the green building certificates increase the weight of sustainable construction materials since the significance of embodied emissions is substantially growing along with the current carbon neutrality goals. As most of the materials for building construction are imported into Iceland, this study is useful for locations similar to Iceland, while overall it is beneficial for the whole world regarding climate change mitigation. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Fire Resistance and Safety of Timber Buildings
(2024-04-21) De Blas, Ira; Amiri, Ali; Insinööritieteiden korkeakoulu; Puustinen, Tuulia
Concerns regarding fire resistance and the safety of timber buildings are relevant since timber buildings are built progressively nowadays. Timber as a material has offered a large number of benefits; therefore, timber is an ideal material in the building and construction industry. This study will explore fire safety challenges such as fire spreads and incidents and provide findings to secure and ensure fire resistance and safety in timber buildings. This study employs a systematic literature review approach to its findings. This study comprised six main sections: Introduction, Background, Methodology, Results, Discussion, and Conclusion. The introduction provides relevant information about fire resistance and the safety of timber buildings and why it is important. The purpose of the background is to analyze and give more details about the already known knowledge about the topic, exploring different aspects such as timber buildings’ history and fire challenges. The methodology section analyzed the method approach used in this study. The result section explored the different findings used in this study. Lastly, findings are analyzed and interpreted in the discussion and conclusion. The findings of this study included the importance of building standards and codes limiting different aspects of timber buildings such as design and architectural design. Fire testing will be also considered since building standards and codes mandate fire testing as it is a way to ensure fire resistance and safety of materials and components. Also, major findings such as limiting fire spread, effective structural and building design, encapsulation, and integrated fire suppression and detection will play an important part in ensuring fire resistance and safety of timber buildings. Practicing and providing these findings in timber buildings ensures that they are fire-resistant and safe. This study contributes to enhancing fire resistance and safety of timber buildings and provides multiple safety methods and techniques to ensure that.
How green building certificates fulfill the environmental goals in the buildings’ life cycle
(Aalto University, 2021) Amiri, Ali; Ottelin, Juudit, Aalto University, Finland; Sorvari, Jaana, Finnish Environment Institute (SYKE), Finland; Rakennetun ympäristön laitos; Department of Built Environment; Real Estate Business; Insinööritieteiden korkeakoulu; School of Engineering; Junnila, Seppo, Prof., Aalto University, Department of Built Environment, Finland
While buildings are responsible for the consumption of nearly 40% of the total energy usage anda large amount of material, they are considered as one of the potential solutions for climate change mitigation. The emissions caused by energy and material use are produced during the life cycle of buildings including pre-use and use stages as the main ones followed by end of life (EoL) stage.The consideration of sustainability and the concern regarding limited natural resources has brought about in the preparation of green building certificates during the last three decades. Among different green building certificates, Building Research Establishment Environmental Assessment Method (BREEAM) is the most widely used while Leadership in Energy and Environmental Design (LEED) is most internationally adopted. This dissertation is going to evaluate green building certificates regarding their fulfillment of reduction in energy and material use via LEED as a reference. Two main stages of pre-use and use are considered while the EoL stage is ignored because of its low contribution. The dissertation is based on four journal articles, and a mixture of qualitative and quantitative methods including literature review, case studies, and statistical data analysis has been used. It was found that, in the use stage, green building certificates have fulfilled the goal of decreasing energy use and emission cut especially at higher levels of certificates but at lower levels the decline in energy consumption is questionable. Regarding the pre-use stage, green building certificates have poorly allocated the points to the materials that have lower environmental impacts like wood.The scenarios of different material selection confirm the lower environmental impacts of wooden buildings based on life-cycle assessment (LCA) as a sustainability evaluation method meaning that it is noteworthy to put more emphasis on material selection in green building certificates. Wooden buildings construction as a recommended solution not only yield fewer emissions during their production compared to concrete and steel ones but also have a significant potential of storing carbon. The study shows that the future environmental plans and regulations by policymakers need continuous updates and modifications in order to find the best solution for climate change mitigation in different locations and times, this applies to green building certificates as well. While the body of research in green buildings has mainly focused on the use stage, there needs to be more attention on the pre-use stage. Besides the motivation for the production of future energy from renewable and clean sources, the embodied emissions which occur in a short time play a significant role in climate change mitigation.
Life Cycle Energy Analysis of Residential Wooden Buildings versus Concrete and Steel Buildings
(2019-12-01) Schenk, Daniela; Amiri, Ali; Insinööritieteiden korkeakoulu; Kokkonen, Teemu
Life cycle energy analysis of residential wooden buildings versus concrete and steel buildings : A review
(FRONTIERS MEDIA SA, 2022-09-28) Schenk, Daniela; Amiri, Ali; Department of Civil Engineering; Department of Built Environment; Structures – Structural Engineering, Mechanics and Computation; Real Estate; Department of Civil Engineering
Around 40% of global energy consumption can be attributed to the construction sector. Consequently, the development of the construction industry towards more sustainable solutions and technologies plays a crucial role in the future of our planet. Various tools and methods have been developed to assess the energy consumption of buildings, one of which is life cycle energy analysis (LCEA). LCEA requires the energy consumption at each stage of the life cycle of a product to be assessed, enabling the comparison of the impact of construction materials on energy consumption. Findings from LCEAs of buildings suggest that timber framed constructions show promising results with respect to energy consumption and sustainability. In this study a critical analysis of 100 case studies from the literature of LCEAs conducted for residential buildings is presented. Based on the studied material, the embodied, operational, and demolition energies for timber, concrete and steel buildings are compared and the importance of sustainable material selection for buildings is highlighted. The results reveal that on average, the embodied energy of timber buildings is 28–47% lower than for concrete and steel buildings respectively. The mean and median values of embodied emissions are 2,92 and 2,97 for timber, 4.08 and 3,95 for concrete, and 5,55 and 5,53 GJ/m2 for steel buildings. Moreover, the data suggests that the energy supply system of residential buildings plays a larger role in the operational energy consumption that the construction material. In addition, climate conditions, insulation detail, windows and building surfaces, and building direction are the other energy use role players. Finally, it was found that the demolition energy contributes only a small amount to the total life cycle energy consumption. This study demonstrates the significance of embodied energy when comparing the life cycle energy requirements of buildings and highlights the need for the development of a more standardised approach to LCEA case studies.
Mycelium-wood composites as a circular material for building insulation
(Frontiers Media, 2024) Candido, Alessia; Amiri, Ali; Junnila, Seppo; Pittau, Francesco; Department of Built Environment; Real Estate; Polytechnic University of Milan
In Europe, buildings account for 40% of the energy consumption and produce 36% of CO2 emissions. Renovation could be a great tool to decarbonize the building stock since it allows for a decrease in the operational energy required for buildings and is less material-consuming than new construction. Further benefits are brought by the usage of bio-based insulation materials that can drastically reduce embodied emissions and transform structures into factual carbon sinks. This study focuses on a particular kind of biogenic material, mycelium-wood composites, consisting of organic matter bound by the root structure of fungal organisms. This innovative insulation material was compared with traditional ones for the renovation of the building stock, with a focus on vertical components like walls in the Helsinki metropolitan area. To characterize mycelium-wood composites, density and carbon content information were gathered from the samples realized in the Politecnico di Milano MaBa.SAPERLab, while the production processes were included in a SimaPro model to obtain the GWP value. Different scenarios were then defined by two variables: the renovation rate of the building stock and the market penetration of mycelium-wood composites. For each scenario, the overall GWP and CO2 stored values were calculated. Results show the great potential of the innovative material that grants carbon storage in the building stock that could even surpass the amount stored in the 32,500 ha of forest in the area. However, this possibility is heavily influenced by factors independent of the type of insulation used that should be further investigated.
The Prioritization of Sustainability Features of Buildings from the Viewpoint of Experts
(MDPI AG, 2023-12-04) Delavar, Taraneh; Amiri, Ali; Borgentorp, Eerika; Junnila, Seppo; Department of Built Environment; Real Estate
The reduction of environmental impact in buildings and the enhancement of environmental performance in the built environment are the key objectives of sustainable development. To achieve this, the adoption of green buildings requires a comprehensive construction approach that focuses on delivering environmentally friendly solutions throughout the entire construction process. This research aims to bridge the gap between theoretical concepts and the practical realities of construction in Iran. It proposes essential criteria and assigns weights to them for creating green buildings based on the opinions of experts from different backgrounds. To understand how buildings are influenced by the environment, society and economics, relevant factors were identified using library research. Web-based surveys involving experts, including architects, engineers, and environmental specialists, were conducted to gather insights into these criteria. A total of 14 criteria were accepted and categorized into economic, environmental, and social dimensions. The Analytic Network Process (ANP) methodology was employed to assess the opinions of 45 expert participants, as provided in the questionnaire. The findings indicate that, among sustainability features, the environmental factor holds the highest significance in Iran, while the social factor is considered the least important. Looking at the sub-criteria, reducing water consumption, financial incentives, and achieving energy efficiency at a reasonable cost are given the highest priority within the environmental, economic, and social aspects of green buildings.
Vihreän rakentamisen kasvupotentiaali Uudellamaalla - UrWood-Loppuraportti
(Aalto University, 2022) Talvitie, Ilmari; Amiri, Ali; Junnila, Seppo; Rakennetun ympäristön laitos; Department of Built Environment; Insinööritieteiden korkeakoulu; School of Engineering
UKKE052 UrWood -tutkimushankkeessa selvitetään puurakentamisen hiilineutraaliuspotentiaali Uudellamaalla sitomalla puun hiilivarannot ja päästövähennykset maankäytön (MAL) tavoitteisiin. Hanke tuottaa uskottavia matalahiili- ja hiilineutraalisuusskenaarioita tulevaisuuden rakentamisesta Uudellamaalla. Arviot perustuvat nyt vallitsevaan rakennustapaan (BAU) sekä erilaisiin puurakentamisen skenaarioihin. Skenaariot kattavat MAL:n sopimuksellisesti keskeiset tavoitteet ja niihin sidotut tavoitevuodet 2031 (MAL), 2035 (Suomen hiilineutraalisuustavoite) ja 2050 (EU hiilineutraalisuustavoite). Hanketta rahoitti Uudenmaan liitto sekä Maa- ja metsätalousministeriö. Hankkeen viestinnässä käytettiin hankkeelle nimeä LANKKU– Laajamittaisen puun käytön hiilineutraaliushyödyt ja kannattavuus rakentamisessa ja kaavoituksessa. Hankkeessa huomioidaan rakentamisen päästöt, puurakennusten hiilivarastot ja hiilikompensaatiot hiilineutraalisuustavoitteihin pyrittäessä. Tutkimus perustuu olemassaoleviin maakäytön tavoitteisiin ja kasvuskenaarioihin uudisrakentamisen määristä Uudellamaalla (Uudenmaan liitto, 2018). Työ hyödyntää aikaisemmin tehtyjä päästömalleja erilaisten puurakennusten ja muiden tämänhetkisten rakennustapojen vertailuissa. Hankkeen keskeisimmät tuotokset ovat eri rakentamisskenaariot ja niiden perusteella annettavat suositukset/arviot puurakentamisen hiilineutraalisuuspotentiaalista Uudellamaalla.Tulokset osoittavat, että puurakentamisella voidaan vähentää uudisrakentamisen ilmastokuormaa sekä kasvattaa merkittävästi kaupunkiympäristöjen hiilivarastoa Uudellamaalla. Puurakentamista lisäämällä voidaan vähentää asuinrakentamisen hiilipäästöjä arviolta noin 0,79–1,35 Mt CO2e. Samaan aikaan rakennetun ympäristön hiilivarasto kasvaisi Uudellamaalla arviolta 0,51–0,80 miljoonaa tonnia, joka vastaa kompensaationa noin 1,88–2,95 Mt CO2e ilmastopäästöjä. Hankkeessa esitetyt arviot uudisrakentamisen päästövähennyksistä pelkästään puurakentamista hyödyntämällä eivät vielä yksistään ole riittäviä saavuttamaan teollisuuden ja kaupunkien asettamaa hiilineutraalisuustavoitetta.Tämän lisäksi tarvitaan merkittäviä muiden rakennusmateriaalien päästövähennyksiä sekä laajamittaisen puurakentamisen hiilikompensaation eli hiilivarastojen kasvattamisen hyödyntämistä. Puurakentamisen lisäksi hanke tutkii matalan ja tiiviin kaupungin konseptia, jolla voitaisiin tukea puurakentamisen nopeaa kasvua ja uudisrakentamisesta aiheutuvan hiilipiikin hillintää. Konseptissa matalalla ja tiiviillä rakentamisella pystytään tuottamaan tiivistä kaupunkirakennetta, mutta samalla tukemaan puurakentamisteknologioiden kilpailukykyä nykyisellä teollisuusrakenteella. Lopuksi UrWood-hankkeessa esitellään myös uusi hiilikompensaatiokonsepti, jossa kaavoitetulle uudisrakennusalueelle sijoitettaisiin systemaattisesti tarpeeksi tiiviisti puurakennuksia niin, että niihin kertyvä hiilivarasto kompensoisi eli pystyisi hyvittämään menetetyn metsämaan hiilivaraston.

Browsing by Author "Amiri, Ali"

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