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Prefabricated timber modules are being increasingly used in the load-bearing structure of entire residential buildings reaching heights up to six stories. The development is driven by the demand of high-quality housing that remains affordable while fulfilling tough environmental requirements imposed on modern construction. To enable further development of this type of buildings additional research is needed despite the considerable number of studies previously performed. This study provides an extensive experimental investigation by subjecting three modules to three different load cases. In each load case, the modules were initially loaded with dead-load placed atop of the module. Thereafter the modules were laterally loaded at the top using a servo hydraulic piston in displacement control. The main aim of the study was to assess the structural behavior of these modules under combined lateral and vertical loading, and also to generate experimental data suitable for verification of finite element models. Results from the test series reveal significant variation in racking stiffness and racking strength depending on the module’s design. Furthermore, in some cases more stiff and stronger mechanical inter-module connections are needed to enhance their global structural performance. Finally, the experimental results reveal that the modules are relatively ductile in their shear response when subjected to horizontal load.

The concept of vulnerability has obtained increased research interest due to the ongoing climate change. The concept has a broad and general meaning which makes it necessary to specify what it actually means in any specific context. In exposure to climate risks, it is important to highlight who and what is vulnerable to climate-related hazards. The concept of social vulnerability derives from ongoing research in disaster, developmental, and socio-geographic sciences. Social vulnerability emphasises the social dimension of vulnerability and how different factors in interaction contribute to influence who is vulnerable. This scoping review is part of a larger project that aimed at increasing the understanding of social vulnerability in a Swedish and Nordic context. The review explores what Nordic literature on vulnerability related to climate hazards has identified as relevant for social vulnerability. 32 articles were included and underwent content analysis. The analysis process was characterised by the involvement of the project group in an iterative cross-disciplinary approach to the topic. This study concludes that social vulnerability is a dynamic process in both time and space; the degree of spatial resolution of vulnerability assessments impacts the possibility to detect vulnerable groups; it is in the combination of factors that social vulnerability emerges; and that the finding of risk perception re-emphasises the agency of the individual.

This work investigates the influence of a single tensile preload, applied prior to fatigue testing, on the fatigue strength of 316L stainless steel parts manufactured using laser-based powder bed fusion (PBF-LB) with a porosity of up to 4 %. The specimens were produced in both the horizontal and vertical build directions and were optionally preloaded to 85 % and 110 % of the yield strength before conducting the fatigue tests. The results indicate a clear tendency of improved fatigue life and fatigue limit with increasing overload in both cases. The fatigue limits increased by 25.8 % and 24.6 % for the horizontally and vertically built specimens, respectively. Extensive modelling and experiments confirmed that there was no significant alteration in the shape and size of the porosity before and after preloading. Therefore, the observed enhancement in fatigue performance was primarily attributed to the imposed local compressive residual stresses around the defects.

Structures built with prefabricated timber modules have been recognised as an innovative construction method and have been implemented in several countries and regions. In recent years, there have been considerable research activities directed towards these types of structures. However, most of the studies have focused on modules made of steel and concrete in their load-bearing structures and only a few of them are exploring light-frame timber modules. This study focuses on the racking behaviour of light-frame timber modules through experimental and numerical investigations. Full-size tests were performed to examine the global and local structural behaviours of several test modules. A novel finite element model of the modules is also presented. It is a parameterised structural model with high flexibility concerning the generation of different module geometries, materials, fastener types and assembly methods etc. The numerical model was developed in the commercial finite element software ABAQUS, and the numerical results obtained were validated against results from experimental tests. The validation results indicate that the model is capable of achieving satisfactory accuracy in predicting both the global and local structural behaviour of light-frame timber modules. Furthermore, several parametric studies are conducted and discussed to examine how certain parameters affect the structural response of the modules.

Previous research has shown a lack of studies with comparisons between primary (virgin) and secondary (re-used) building materials, and their embodied emissions. The creation of different scenarios comparing the environmental impact of virgin vs. re-used materials is also motivated by the scarcity of raw materials in the world and the emergency of mitigating greenhouse gas (GHG) emissions from buildings. The aim of this study was to investigate scenarios, including new vs. re-used building products, applying the LCA method for a wooden single-family building. The findings showed a 23% reduction potential for total released (positive) CO2e when comparing the Reference scenario with Scenario I, using re-used wooden-based materials. Further, Scenario II, using all re-used building materials except for installations, showed a 59% CO2e reduction potential compared to the Reference scenario. Finally, Scenario III, which assumes all re-used building products, showed a 92% decreased global warming potential (GWP) impact compared to the Reference scenario. However, when including biogenic carbon and benefits (A5 and D module), the Reference scenario, based on newly produced wooden building materials, has the largest negative GHG emissions. It can be concluded that the re-use of building products leads to significant carbon savings compared to using new building products.

In this study, a numerical model that aimed to predict the strength and stiffness, of a single laterally loaded mechanical fastener in steel-to-cross laminated timber (CLT) connections using a Beam-on-Foundation (BoF) model, is presented. The BoF model was used to predict the ductile failure modes of steel-to-CLT connections and considered the layered structure of CLT. When compared to the European Yield Model (EYM), the BoF model was found to be advantageous as it not only predicted the strength but also the stiffness of the connections. A comparison of the slip modulus and strength from BoF model simulations of experimental tests carried out on steel-to-CLT connections showed good agreement with the experimental results. Using the BoF model, the influence of; (i) density, (ii) deck layer orientation, (iii) embedment behaviour, (iv) dowel diameter, (v) steel plate thickness, and (vi) embedment length, on steel-to-CLT connections was investigated in a parameter study. The results presented herein highlight the benefit of the BoF model that considers CLT layer specific embedment behaviour in determining the shear capacity and stiffness of steel-to-CLT connections.

Producing cross-laminated timber (CLT) has opened a new market for the lumber industry in North America, while few hardwood species have been studied in the U.S. for CLT production. Combining hardwood species in mixed hardwood CLT or in hybrid CLT can be a solution to boost the market of the undervalued hardwoods. However, the knowledge gap on bonding hardwoods needs to be filled to provide evidence of feasibility. This study focused on the face bonding properties of the cross laminations made of seven hardwood species and two softwood species from the Great Lakes region using two commercial structural adhesives, the phenol resorcinol adhesive (the Resorcinol) and the melamine urea formaldehyde adhesive (the Melamine). A total of 45 combinations of the selected species were studied for the bonding strength (shear under compression) and the percentage of wood failure. For single species samples, the bond strength was positively related to the specific gravity of wood and the bond strength of hardwoods was 33% and 82% stronger than that of softwoods bonded with the Resorcinol and the Melamine respectively. The mixed hardwoods showed higher bonding strength (the Melamine: 5.45 MPa, the Resorcinol: 5.28 MPa) than mixed softwoods (the Melamine: 2.8 MPa and the Resorcinol: 2.7 MPa). Among the Resorcinol bonded mixed combinations, 54% had a percentage of wood failure less than 80%, while the Melamine bonded had only 4 out of 22 which had a percentage of wood failure less than 80%. The overall bonding strength of the hybrid combinations was 5% weaker than that of the mixed hardwoods. All hybrid combinations bonded with the Melamine met the 80% wood failure criterium, but some bonded with the Resorcinol had a percentage of wood failure less than 80%. Anatomical features, especially pore distribution, played a key role in the bonding performance. However, the Melamine adhesive consistently achieved over 80% wood failure across all pore distribution types.

W artykule przedstawiono wyniki badań krótkotrwałych i reologicznych przyrostu odkształceń w teście wypychania (push-out test) w przypadku dwuzakładkowych połączeńklejonych. Łącznie przebadano 15 próbek złożonych z elementów wykonanych z drewna klejonego krzyżowo (CLT) oraz prefabrykowanych płyt betonowych. Połączenie między elementami wykonano jako klejone z użyciem innowacyjnych prefabrykowanych złączy podatnych o grubości 3 mm, w trzech konfiguracjach powierzchni klejenia. Celem badań było określeniewpływu geometrii połączenia klejonego na początkowy przyrostodkształceń w czasie. Wykazano, że pełzanie przebiega nieliniowo w czasie t1 = 800 s niezależnie od powierzchni klejenia, a następnie zwiększa się w sposób liniowy. W przeprowadzonych badaniach złączy pasmowych uzyskano przyrost początkowegopełzania o ok. 10% mniejszy w przypadku złączy ułożonychw kierunku obciążenia niż w kierunku prostopadłym. Wykazano również, że wartości pełzania nie są wprost proporcjonalnedo wielkości naprężenia ścinającego., This paper presents the results of a study of short-termrheological strain increments in a push-out test for double-lapglued joints. A total of 15 specimens consisting of crosslaminated timber (CLT) elements and precast concrete slabs weretested. The joint between the elements was made as a glued jointusing innovative 3 mm thick prefabricated flexible jointsin threebonding configurations. The aim of the study was to investigatethe influence of the adhesive joint geometry (typeAwith 600 cm2glue, B – 200 cm2 in strips parallel to the load axis and C – 200 cm2in strips in the perpendicular direction) on the initial deformationincrease over time. Creep phenomenon was shown to be nonlinear for an initial time range of t1 = 800 s regardless of theadhesive area, and then to increase in a linear manner. In the testscarried out on strip joints, the increments of initial creep wereobtained to be about 10% smaller for joints arranged in the loaddirection than for those arranged in the perpendicular one. It wasalso shown that the creep values are not directly proportional tothe magnitude of the shear stress.

Wood is a sustainable material from nature that has a longstanding traditionas a building material. Compared to other construction materials, such as steeland concrete, the significance of using structural timber and engineered wood products has increased in recent years because they are regarded as a renewable source and require a low carbon footprint and less energy consumption during production. In Scandinavia, the European design standard EN 1995-1-1 (EC5) is extensively used to guide structural engineers in the design of timber structures, while addressing safety and service ability issues. However, this standard relieson multiple simplifications to achieve simple semi empirical hand calculations. In addition to these simplified expressions, engineers and researchers need reliable numerical models to study the racking behaviour of light-frame timber structures with arbitrary geometry under complex loading conditions. Such modelling tools must be computationally effective, easy to use and able to simulate the global structural behaviour as well as the local fastener force distributions and the crack growth in the sheathing panels.The main aim of this doctoral thesis is to develop a numerical model to analyse the complex structural behaviour of prefabricated light-frame timber modules. The model is developed in the commercial finite element software ABAQUS® with the assistance of the parametric Python scripting method. This thesis work also includes development of a graphical user interface in Python for user-friendly inputs, outputs, and visualisation of the numerical results. The simulation tool was used to study two different structural applications, firstly light-frame timber walls and then light-frame timber modules. For these applications, the modelling of the mechanical sheathing-to-framing joints is very important. In the first paper application, oriented and uncoupled elastic spring-based connectors were used to simulate the sheathing-to-framing joints.

This study investigates the thermal and energetic dynamics of primary school classrooms in a Mediterranean climate in Khoualed Abdel Hakeem, Ain Temouchent County, Algeria. The research highlights significant optimizations by focusing on passive strategies such as external shading devices, Window-to-Wall Ratio (WWR), glazing types, and building envelope adjustments. Our simulations, validated rigorously, showcase a remarkable congruence with actual electricity consumption, affirming the reliability and efficacy of our simulation model as a valuable predictive tool. A Vertical Shading Angle (VSA) of 60° proves optimal, resulting in an impressive 11% reduction in Annual Energy Consumption (AEC). A recommended WWR of 30% demonstrates an 11% decrease in AEC and improves thermal and energy efficiency. Double Low Emissivity (Double-Low E) glazing is found to be superior, resulting in a significant 14% decrease in AEC. Achieving a WWR of 50% in shaded areas helps maintain a well-balanced thermal environment, resulting in a 12% reduction in heating and cooling requirements. The integration of passive strategies in the optimized model showcases a remarkable 44% overall reduction in energy consumption. The results highlight the efficacy of passive strategies, promoting energy-conscious and ecologically responsible practices, advocating for their incorporation in educational facilities, and offering valuable insights for sustainable school building design., QC 20240527

The European Union (EU) has implemented several policies to enhance energy efficiency. Among these policies is the objective of achieving energy-efficient renovations in at least 3% of EU buildings annually. The primary aim of this study was to offer a precise environmental comparison among four similar district-heated multifamily buildings that have undergone identical energy efficiency measures. The key distinguishing factor among them lies in the HVAC systems installed. The chosen systems were as follows: (1) exhaust ventilation with air pressure control; (2) mechanical ventilation with heat recovery; (3) exhaust ventilation with an exhaust air heat pump; and (4) exhaust ventilation with an exhaust air heat pump with a Photovoltaic (PV) panel. This study involved a life cycle assessment that relied on actual material data from the housing company and energy consumption measurements. This study covered a period of 50 years for thorough analysis. A sensitivity analysis was also conducted to account for various future scenarios of energy production. The findings revealed that the building with an exhaust air heat pump exhibited the lowest greenhouse gas emissions and the shortest carbon payback period (GBPT), needing only around 7 years. In contrast, the building with exhaust ventilation without heat recovery showed the highest emissions and the longest carbon payback period (GBPT), requiring approximately 11 years. Notably, the results were significantly influenced by future scenarios of energy production, emphasizing the crucial role of emission factors in determining the environmental performance of distinct renovation scenarios.

A wider deployment of nearly zero energy buildings (NZEBs) is expected to contribute to the transition to a decarbonized and energy-efficient building sector in Europe. This study proposed an integrated energy-economic analysis to exemplify the feasibility of NZEB renovation in temperate climate. A parametric analysis was performed to identify technical building system configurations that give minimum share of renewable energy systems contributing to NZEB level. Final energy savings, global costs and cost-effectiveness of renovating a building to NZEB level are analysed, considering active and passive energy efficiency measures (EEMs). The active EEMs included efficient water taps and heat recovery ventilation, and the passive EEMs encompassed insulations to roof, exterior walls and ground floor, and improvements of windows and doors. The building had initial final energy use of 133 kWh/m2 year for space heating, domestic hot water production (DHW) and facility electricity. The results show that NZEB level is achieved with active and passive EEMs, without renewable energy systems for scenarios with low discount rates and high future energy price escalations. The annual final energy use for space heating, DHW and facility electricity is reduced cost-effectively by 37-54%. Furthermore, increasing size of PV-system enhanced cost-effectiveness by lowering total global costs.

Lighting in the built environment affects different aspects, ranging from building performance in terms of costs and energy consumption to human well-being in terms of thermal comfort, visual effects, and beyond-vision effects. Buildings optimised for specific performance metrics rarely consider different aspects simultaneously, leading to sub-optimised, unbalanced, or non-trade-off solutions. Therefore, multi-objective optimisation has commonly been used to overcome conflicting performance objectives. Recently, light effects beyond vision gained more interest in building design but it is unclear if and how they are integrated with other existing building performance metrics and simulation workflows. A scoping review investigated the state-of-art in multi-objective lighting design optimisation regarding building performance and human well-being focusing on performance metrics, simulation workflows, and the overall information flow. Results show that metrics for beyond-vision effects are not integrated with other human well-being and building performance metrics. The simulation workflows included multiple steps and computational tools in multi-objective optimisation. This process has limitations such as a long simulation time, no ubiquitous integrated tool, and a reduced information flow.

In a ventilated room, the indoor airflows are complicated but can generally be defined by an internal recirculating airflow generated by flooding of ventilation air. This concept categorizes the internal room flow (air and contaminants) as consist of two populations: One leaving the room and the other recirculating. The one recirculating is spreading the contaminants while the one leaving is evacuating the contaminants, which are quantified by the transfer probability between the source and other locations in the room and by purging flow rate, respectively. This concept accounts for spatial and temporal aspects in risk of airborne infection transmission. The current paper proposes and discusses a revised risk infection model based on this concept and has demonstrated applicability of the model with a test measurement setup with both mixing and displacement ventilation systems. The results emphasize the importance of considering both spatial and temporal factors in assessing airborne infection risks. It underscores the need for dynamic models like the proposed revised Wells-Riley model to provide a more accurate representation of infection risks in various indoor environments. Additionally, it discusses the necessity for longer measurement periods to fully understand the evolving nature of these risks.

The time constant of ventilation of rooms in buildings is between 15 minutes (in office spaces) to 2 hours (in residential buildings). Currently, most of the tracer gas system analyzers on the market have a minute-based time constant and depending on the channels a cycle of sampling and analysis may take up to 6 minutes, E.g., 6 channel system. Essentially, only mean values are recorded with most present tracer gas analyzers. This is a hindrance for detailed temporal analysis of conditions in the room and consequently is does not capture the resolution of the influence of the internal flow on air and contaminant distribution. The current paper presents work on the development and testing of a fast response CO2 tracer-gas system with a time constant of 1 second. In contrast to the present analyzers, not only the mean values but also the whole statistical distribution of variables can be recorded, and pulse responses can be analyzed. This makes the system viable for measurement and analysis of not only spatial but also temporal distribution of contaminants. For example, recirculating airflow in the room generated by flooding of ventilation air is possible to be measured and thus making it easy to extend the analyses of the process of ventilation far beyond the possibilities with current systems.

The building sector is responsible for 34% of final energy consumption and contributes to 37% of global CO2 emissions. In alignment with sustainability goals, the European Union has set a target to reduce CO2 emissions in the building sector by up to 90% by 2050. Consequently, there is a great need to examine the climate impact of buildings and adopt a comprehensive perspective using a whole life carbon assessment. The aim of the thesis was to examine greenhouse gas (GHG) emissions and costs throughout all life cycle stages, applying a whole life carbon assessment and life cycle cost analysis for a single-family building situated in a Nordic climate. Additionally, both positive (released) and negative GHG emissions were explored and documented, encompassing operational and embodied impacts. In the thesis, the life cycle assessment and the life cycle cost methods have been applied by following the “cradle-to-grave” life cycle perspective. The study includes an analysis of the reference building design and comparisons with improved building design. The thesis findings highlight a substantial decrease in released GHG emissions with 23% reduction for the analyzed improved building design showing 5.2 kg CO2e/m2/y50 compared to the reference building design showing 6.7 kg CO2e/m2/y50. Moreover, incorporating biogenic carbon and the D module into the cradle-to-grave approach shows the lowest total GHG emissions, manifesting as negative values, -0.7 kg CO2e/m2/y50 for the improved building design. Embodied impact accounts for 79% and 72% of the total impact, while operational impact accounts for 21% and 28% for the reference and improved building designs. When analyzing all building materials, it is shown that an increased share of wooden building materials in the improved building design results in decreased released (positive) GHG emissions and increased negative GHG emissions. The results underscore the significance of using wood-based building materials due to their ma, Byggsektorn är ansvarig för 34% av slutlig energiförbrukning och bidrar till 37% av de globala CO2-utsläppen. I linje med hållbarhetsmålen har Europeiska unionen satt som mål att minska CO2-utsläppen inom byggsektorn med upp till 90% till år 2050. Följaktligen finns det ett stort behov av att undersöka byggnaders klimatpåverkan och anta ett helhetsperspektiv genom att använda livscykelanalys av koldioxid. Syftet med avhandlingen var att undersöka koldioxidutsläpp (växthusgasutsläpp) och kostnader under alla livscykelstadier genom att tillämpa en hel livscykelanalys och livscykelkostnadsanalys för ett enfamiljshus i ett nordiskt klimat. Dessutom undersöktes och dokumenterades både positiva (utsläppta) och negativa växthusgasutsläpp, som innefattade påverkan från både produktion och användning. I avhandlingen har metoderna livscykelanalys och livscykelkostnadsanalys använts med ett ”vagga-till-grav” livscykelperspektiv. Studien inkluderar en analys av referensbyggnadens utformning samt jämförelser med förbättrade utformningar av byggnaden. Avhandlingens resultat lyfter fram att växthusgasutsläppen minskar med 23% för den analyserade förbättrade utformningen av byggnaden, som ger 5.2 kg CO2e/m2/y50 jämfört med referensbyggnadens utformning som ger 6.7 kg CO2e/m2/y50. Dessutom, när biogen koldioxid och D-modulen inkluderas i livscykelanalysen från vaggan till graven visar sig de lägsta totala (växthusgas)utsläppen, som innebär negativa värden, -0.7 kg CO2e/m2/y50 för den förbättrade utformningen av byggnaden. Påverkan från produktion av material och produkter står för 79% och 72% av den totala påverkan (på koldioxidutsläppen), medan påverkan från driften står för 21% och 28% för referens- och förbättrad byggnadsdesign. När alla byggnadsmaterial analyseras visar det sig att en ökad andel av byggnadsmaterial av trä i den förbättrade utformningen av byggnaden resulterar i en minskning av utsläppta (positiva) växthusgasutsläpp och ökade negativa växthusgasutsläpp. Resultate

This study is aimed at investigating those parameters related to timber fooring that can afect the acceptability of vibration behaviour of a timber foor in a residential building in view of the criteria stated in Eurocode EC5. The timber foor investigated is made of OSB/3 foorboards and timber joists. The parameters that are investigated in this study are thickness of fooring, foor joist span, joist spacing and connection of foorboards to the joists. In this context, two cases are considered. First: the fooring is nailed or screwed to the joists and no composite action or interaction is obtained between joists and foorboards. Second: the fooring is glued sufciently to the joists and full interaction is obtained. The result suggests that glued foorboards perform much better with respect to natural frequency, static defection and peak foor velocity than nailed or screwed foorboards. In almost all cases of glued foorboards, the result complies fully with the Eurocode 5 design vibration requirements. However, as foor lengths increase, the static defection will increase beyond the allowable limit, especially for relatively thin foor panels and relatively widely spread joists. For both cases, increasing foorboards thickness and decreasing the joist span by adding more beams can yield even better results to satisfy the requirement of vibration comfort., Funding: Linkping University

The development of high-rise buildings worldwide has given rise to significant concerns regarding their excessive electricity consumption. Among the various categories of high-rise structures, hotels used for business and conferences stand out as particularly extravagant in their energy use. The consequence arising from excessive energy usage is an escalation in carbon emissions, which is a primary driver of global warming. Therefore, this study aims to investigate the energy use intensity (EUI) of a hotel building located in Jakarta, Indonesia. In order to improve energy performance, this study explored various options for renovating the building envelope, such as incorporating insulation and a roof covering, as well as implementing building-integrated photovoltaics (BIPV). The building envelope renovations demonstrated a notable reduction in energy use by 15.8–27.7% per year. BIPV, such as curtain walls and double-skin façades, generated an energy use reduction of 4.8–8.6% per year. Remarkably, by combining the two approaches (i.e., adding insulation and a roof covering in the building envelope and adopting BIPV as double-skin façades), the potential reduction in energy use reached up to 32.2% per year. The findings can assist decision-makers in developing building renovation strategies for high-rise buildings while considering energy conservation.

Daylight, both outdoors and indoors, is essential for human well-being. However, daylight provision often faces challenges in various climates and locations, due to factors such as shortcomings in regulations, urban densification, deregulation or special exemptions, and the limitations of existing daylight and sunlight evaluation methods. To address these issues, we propose the Sunlight Autonomy, a new methodology and set of metrics, that aims to overcome the limitations of existing early-stage daylighting metrics and is valuable for urban planning and architectural design purposes., Theme of the conference: Daylight in the service of Sustainable Development Goals: a colourful spectrum of opportunitiesQC 20240605

Extrusion-based 3D concrete printing (3DCP) is a promising technique for fabricating complex concrete elements without formwork, offering advantages like cost reduction and enhanced design flexibility by decoupling manufacturing costs from part complexity. However, this extended formal freedom is still constrained by the fabrication process and material properties. This paper presents a novel method for applying topology optimisation internally i.e. preserving the external boundaries of the concrete element while reducing material use and weight. This method adapts the extrusion thickness along the part according to the expected stresses, reducing the material use while enhancing structural performance. To validate this method, three different unreinforced 3DCP beams are tested in three-point bending. Results show that beams with optimised material distributions presented a higher strength-to-weight ratio, averaging 47% and 63% compared with the conventional 3D printed beam. This paper demonstrates the potential of internal topology optimisation for improving the efficiency and sustainability of 3DCP., QC 20240515This project has received support from Hesselmanska Foundation, the Development Fund of the Swedish Construction Industry (SBUF) 13791, and the strategic innovation program Smart Built Environment (2020-00257), which is part of the strategic innovation areas initiative funded by Vinnova — the Swedish Innovation Agency, Formas — a Swedish Research Council for Sustainable Development and the Swedish Energy Agency. Printable material for 3DCP experiments was supplied by Sika (Sika Sverige AB).

Recent advancements in the fields of artificial intelligence, machine learning, and the Internetof Things have created opportunities to improve the performance, safety, and energyefficiency of building ventilation. This report explores the current state of AI technologiesin building ventilation and indoor air quality management by highlighting applications oftechnologies related to air quality monitoring, control, predictive maintenance, and energyoptimization. The report also examines the ethical and data privacy issues associated withdeploying these technologies and advocates AI integration in building HVAC systems byidentifying future challenges and avenues for research., QC 20240524

Recent advancements in the fields of artificial intelligence, machine learning, and the Internetof Things have created opportunities to improve the performance, safety, and energyefficiency of building ventilation. This report explores the current state of AI technologiesin building ventilation and indoor air quality management by highlighting applications oftechnologies related to air quality monitoring, control, predictive maintenance, and energyoptimization. The report also examines the ethical and data privacy issues associated withdeploying these technologies and advocates AI integration in building HVAC systems byidentifying future challenges and avenues for research., QC 20240524

Raw data will successively be uploaded here for the study "Wind tunnel and numerical study of wind pressure coefficients on amedieval Swedish church".

A reliable determination of the embedment strength and foundation modulus of timber elements is critical for the design and safety assessment of joints in timber structures. However, the existence of various test configurations for characterising the embedding properties of large diameter steel fasteners in timber elements poses challenges in directly comparing and utilising available test data. This paper aims to provide an insight into the influence of embedment property test methods, comparing experimental results from different test setups within the guidelines of the EN 383 and ASTM D 5764-97a standards for European softwood species, Scots pine wood (Pinus sylvestris) and Norway spruce (Picea abies). In addition to the test guidelines, the thickness of the specimen and the application of the load was evaluated within the protocols. A comprehensive statistical analysis was performed to identify statistically significant differences between the groups evaluated. The results of the analysis revealed disagreement between the standards in the evaluation of the strength of the embedding, highlighting the potential bias inserted by the experimental setup and protocol. Furthermore, it was proven that the thickness of the specimens influences both the embedding strength and the foundation modulus of the wood species tested. Finally, no distinctions were observed between tensile and compressive loading within the guidelines of the EN 383 standard., Bibliografiskt granskad

Precast prestressed hollow core (HC) floors are widely used in various applica-tions within the construction sector. Such floors are usually designed as single,simply supported elements, although it is known that individual elementsforming the floor interact with each other. This article presents the state of theart regarding load redistribution in HC floors in the light of experimental data,current analytical models and code provisions. While this phenomenon iswidely known and recognized, only sparse, and often poorly documentedexperimental data are available, which represent the basis for the assessmentand calibration of analytical models. Moreover, even though the availablemodels and code provisions share similar assumptions, their outcomes are insome cases conflicting. Having recognized the existing knowledge gap, theauthors outline future perspectives for the development of consistent analyticaland numerical approaches supplemented by new experimental data.

Concrete is the most used building material. With the increasing growth of industries and urbanization globally; the demand for concrete is increasing significantly. Ordinary Portland Cement (PC) is the binder used to produce typical concrete. Unfortunately, for every ton of manufactured cement about 0.61-ton CO2 is emitted into the earth’s atmosphere. As a result, several solutions have been implemented to reduce the usage of this material in the production of concrete. This includes its partial or full replacement with supplementary cementitious materials (SCMs) or alternative binders. Some of these combinations could be problematic to be used in cold climates due to a lower developed hydration heat, slower setting, or worse frost durability. In winter the immediate exposure of fresh concrete to freezing temperatures results in pore ice formation and could delay or completely stop the hydration process. This is commonly prevented by using an additional heating system installed in concrete or the formwork. Unfortunately, usually, it adds complexity, increases the price, and depending on the used power source, could increase the CO2 footprint. Another potentially simpler and more sustainable solution is to modify the concrete itself by adjusting the mix design, by using certain chemical admixtures and special cementitious binders. This research aimed to better understand how partial replacement of Portland cement with GGBFS and/or CSA cement affects the properties of concretes exposed to freezing and subfreezing temperatures in a fresh state and at a young age. The secondary aim was to evaluate a possible application of UHPC to protect new and existing concrete structures from frost damage. The research included a literature review of methods used to produce concrete structures at zero and subzero temperatures. A special emphasis was on the application of chemical and mineral admixtures that could eliminate the need to use heat treatments. The output of this analysi

The house-building industry is increasingly recognizing the importance of information, viewing it as key for driving sustainable construction. This acknowledgment highlights that informed decision-making, based on the effective use of information, can enhance all phases of house-building. Sustainable house-building demands an integration of diverse information, technologies, and standards, necessitating the increased use of information to support decision-making. In response, the industry is focusing more on the capture, management, and storage of information. Despite significant investments in these areas, the full potential of this information is not yet realized due to the lack of and poor use of structured information systems. Furthermore, the information produced is often tailored for specific segments, leading to the creation of information silos that isolate data, making it difficult to collaborate across different stakeholder groups. While the benefits of structured information are widely acknowledged, the integration of structured data and information technologies in house building is impeded by unintuitive and fragmented information management practices. Additionally, many current information systems in the industry still emulate paper-based document structures, continuing the use of unstructured and non-standardized data. To address these challenges, this thesis explores the development of information structures that facilitate reusability across house-building projects and explores the integration of visualization techniques into these development methodologies. By employing cross-case analysis as the scientific method, this study evaluates findings from multiple cases to identify common themes and patterns, thereby enhancing the understanding of the observed phenomena by effectively comparing and contrasting findings from individual case studies. The findings of this thesis underscores the delicate balance required in information structures to effective

Environmental variations of Temperature (T) and Relative Humidity (RH) in air cause a superficial and/or sub -surface deformation (shrinkage/swelling) of organic hygroscopic objects, as for example wood. These environmental variations may be due to the natural variability of climate, to the use of Heating, Ventilation and Air Conditioning (HVAC) systems and to the presence of people. This contribution focuses on a group of wooden rural churches located in harsh climates in Sweden. The churches, which are still in use for the local communities, are heated during wintertime to reach acceptable indoor comfort levels causing potentially risky T and RH fluctuations for hygroscopic objects. In this framework, the main goal is assessing the risk of fracture on wooden structural elements caused by hygrothermal fluctuations. The method is based on a preliminary approach for reconstructing the climate history experienced by a typical wooden structural element of these churches and that, over time, results in a cyclic fatigue loading, naturally induced by the outdoor climate. Then, the effect of the artificial heating on the indoor microclimate and, therefore, on the reconstructed fatigue curve is assessed. Main outcomes were obtained by using a methodology that is preliminary based on simplifying assumptions, due to a severe lack of knowledge, in literature, about the fatigue behavior of wood. Finally, main considerations on the fatigue behavior of exposed wooden elements are drawn up, namely the estimation of their residual life (or "lifeto -damage"), which may support conservators or church managers in better managing the microclimate to reduce the risk of fracture on valuable objects.

Timber-concrete hybrid buildings are an innovative solution to increase the amount of timber materials in modern buildings. Due to its lower impact on the environment than materials like steel and concrete, the demand for timber products is rising as the construction industry aims to decrease its environmental footprint.Timber is naturally grown, and certain characteristics must be considered when used in buildings, such as strength and stiffness properties depending on variables like fiber direction and moisture content. In addition, timber is a lightweight material, which influences dynamic performance of timber elements and structures.To fulfill the requirements of a modern building, timber elements are sometimes combined with concrete elements, introducing timber-concrete hybrid buildings.This study aims to expand the use of timber-concrete hybrid buildings within the construction industry. The objective is to present different types of timber-concrete hybrid buildings and evaluate their structural performance to improve the level of knowledge for structural designers for the safe and robust design of such buildings. Typically, four different types of timber-concrete hybrid structures are found in building projects in Sweden. These types of building projects usually involve additional designers than regular projects due to a lack of knowledge in timber design. Additionally, different designers uses different statical models for their designs, even within the same building project. A mobile measurement system was developed to perform in-situ dynamic measurements. The system was used in a nine-story timber-concrete hybrid building during construction to investigate the dynamic properties and validate structural design models. A parameter study highlights different design parameters that have a large influence on these models. These parameters include the inplane shear stiffness of CLT wall elements, the foundation properties, as well as non-load-bearing internal w, Hybridkonstruktioner i trä och betong är en innovativ lösning för att öka andelen trämaterial som används i dagens byggnader. På grund av träets fördelaktiga klimategenskaper i jämförelse mot traditionella byggmaterial som t.ex. stål och betong, har både utbudet av träprodukter och efterfrågan på dessa ökat. Då trä är en naturlig råvara, finns det vissa egenskaper som måste beaktas när det används för byggproduktion. Som exempel påverkas styvhet och hållfasthet av variabler som fiberriktning och fuktkvot. Dessutom är trä ett material med förhållandevis låg densitet, som påverkar den dynamiska prestandan i byggnader som använder bärande träelement. För att möta de krav som ställs på dagens byggnader, kombineras i flera fall bärande element i trä med bärande element i betong. Denna typ av byggnad kallas hybridkonstruktioner i trä och betong. Arbetet syftar på att öka andelen hybridkonstruktioner inom byggsektorn. Målet med denna studie är att utvärdera hur den här typen av byggnader beter sig för att kunna ge konstruktörer ökad kunskap om säker och robust dimensionering. Det här arbetet presenterar fyra olika typer av hybridkonstruktioner i trä och betong som används i Sverige. I den här typen av projekt används fler konstruktörer än i traditionella byggnadsprojekt, detta då kompetensen inom träkonstruktion är bristfällig hos de traditionella konstruktörerna. Dessutom använder konstruktörer olika antaganden och statiska modeller för sina beräkningar, även om de gäller samma byggnad. Ett mobilt mätsystem har utvecklats för att kunna genomföra dynamiska mätningar på plats. Under byggtiden av ett 9-vånings flerbostadshus har det mobila mätsystemet använts för att fånga in dess dynamiska egenskaper och för att validera beräkningsmodeller. En jämförande studie visade vilka parametrar som i hög grad påverkar resultaten i dessa modeller. De avgörande parametrarna var främst skjuvstyvheten i KL-träväggarna, grundläggningen, samt icke-bärande innerväggar. Långtidsmätningar av

Over half of the world’s population live in urban areas, a trend which is expected to only grow as we move further into the future. With this increasing trend in urbanisation, challenges are presented in the form of the management of urban infrastructure systems. As an essential infrastructure of any city, the energy system presents itself as one of the biggest challenges. Indeed, as cities expand in population and economically, global energy consumption increases, and as a result, so do greenhouse gas (GHG) emissions. Key to realising the goals as laid out by the 2030 Agenda for Sustainable Development, is the energy transition - embodied in the goals pertaining to affordable and clean energy, sustainable cities and communities, and climate action. Renewable energy systems (RESs) and energy efficiency have been shown as key strategies towards achieving these goals. While the building sector is considered to be one of the biggest contributors to climate change, it is also seen as an area with many opportunities for realising the energy transition. Indeed, the emergence of the smart city and the internet of things (IoT), alongside Photovoltaic and battery technology, offers opportunities for both the smart management of buildings, as well as the opportunity to form self-sufficient peer-to-peer (P2P) electricity trading communities. Within this context, advanced building control offers significant potential for mitigating global warming, grid instability, soaring energy costs, and exposure to poor indoor building climates. Most advanced control strategies, however, rely on complex mathematical models, which require a great deal of expertise to construct, thereby costing in time and money, and are unlikely to be frequently updated - which can lead to sub-optimal or even wrong performance. Furthermore, arriving at solutions in economic settings as complex and dynamic as the P2P electricity markets referred to above, often leads to solutions that are computationally intr

Building design typically has a focus on energy use and economy. The indoor environment is often overlooked or simplified to such an extent that essential aspects are neglected. Additionally, introducing technologies for improving energy efficiency can also affect the indoor thermal climate and, in turn, the perceived indoor comfort. Furthermore, an energy efficiency measure which creates discomfort could end up ineffective due to occupant behaviour. The main objective of this thesis is to demonstrate why indoor thermal comfort is vital to consider during building design or renovation procedures. It also explores some methods for improving the sub-Arctic region related to this matter. In this thesis, six different residential buildings have been studied within the northernmost region of Sweden—Norrbotten. This region is sub-Arctic, with long, cold and dark winters. The summers are brief but bright and relatively warm. In this thesis, the winter cases are in focus, but summer cases are also assessed to a minor degree. Both energy usage and indoor thermal climate parameters were measured throughout the buildings. The results indicate a need to assess implemented energy efficiency measures. The results also show the importance of considering the indoor thermal climate during energy efficiency measures. The thesis also discusses the use of the popular building performance simulation (BPS) software package IDA ICE. The software package performed well when calculating and predicting energy use and balance. However, IDA ICE could not detect certain indoor thermal climate problems. In these cases, some surface temperatures were incorrect in IDA ICE models, where warm radiator surfaces were the most evident. The error led to the radiation temperatures being too low, affecting thermal comfort parameters such as the predicted percentage of dissatisfied (PPD). The error could give a false impression of thermal comfort. Computational fluid dynamics (CFD) simulations can acquire

The ability to offer unique solutions that meet customer demands has been considered a competitive advantage in the industrialised house building (IHB) industry. However, IHB companies are struggling due to varying customer needs and the simultaneous need to fulfil legal regulations, market demands, and production constraints. This has forced companies to develop unique solutions for every housing project to satisfy individual requirements, which automatically drives them to follow an engineer-to-order (ETO)-based strategy. The high involvement of customers in the design process results in the need for considerable engineering activities to validate and adjust to the customer demands, thereby providing individualised solutions. Moreover, designers adopt different production strategies based on the degree of pre-engineering. Product platform approaches have been acknowledged as one of the prominent means to improve both internal and external efficiencies. However, the use of traditional platform-based strategies does not suffice for the design of ETO-based components in an IHB system. A systematic approach is required to align the product platform and different production strategies so that customer requirements can be easily managed. Thus, this research aims to outline the means to support the design phase of IHB by applying a product platform approach when using a mixed production strategy. A Swedish multi-storey house building company that uses a glulam-based post and beam building system was used as the main case in this research. Empirical data were collected mainly from interviews, observations, workshops, and document analysis. This research proposes a framework for the systematic development and use of the product platform by following an inductive approach. Further, a parametric design platform method is proposed to achieve a platform-based development for ETO-based components by identifying, formalising, and reusing the design assets. The findings reveal ho, Förmågan att erbjuda unika lösningar som möter kundernas krav har ansetts vara en konkurrensfördel inom industriellt husbyggande (IHB). Dock, utmaningen för IHB-företag handlar om att kunna balansera varierande kundbehov med behovet att uppfylla juridiska regler, marknadskrav och produktionsbegränsningar. Följden är att företag har tvingats att utveckla unika lösningar för varje nytt bostadsprojekt för att därigenom tillgodose individuella krav, vilket automatiskt driver dem till att följa en Engineer-toorder (ETO)-baserad strategi. Kundernas engagemang i projekteringsprocessen kräver ingenjörsmässiga aktiviteter för att bekräfta och anpassa sig till kraven och erbjuda kundunika lösningar. Dessutom,beroende på nivån av förprojektering antar projektörerna olika produktionsstrategier. Produktplattformar har accepterats som ett sätt för att förbättra både intern och extern effektivitet. Användningen av traditionella plattformsbaserade strategier räcker dock inte för framtagning av ETO-baserade komponenter i ett industriellt byggsystem. Det krävs ett systematiskt tillvägagångssätt för att anpassa produktplattformen och de olika produktionsstrategierna så att kundernas krav kan hanteras. Därför syftar denna avhandling till att bestämma de resurser som krävs för att stödja projekteringsfasen av IHB genom att tillämpa produktplattformar när en mixad produktionsstrategi tillämpas. Ett svenskt industriellt husföretag med flervåningshus som använder ett limträbaserat pelar-balkbyggsystem har varit huvudfall. Empiriska data har samlats in från intervjuer, observationer, workshops och dokumentanalyser. Resultaten tar fram ett ramverk för systematisk utveckling och användning av produktplattformar genom att följa ett induktivt tillvägagångssätt. Vidare föreslås en parametrisk designplattformsmetod för att uppnå en plattformsbaserad utveckling för ETO-baserade komponenter genom att identifiera, formalisera och återanvända tillgångarna från projekteringen. Resultaten visar hur öve

Trä i byggnader som exponeras för fukt eller fritt vatten blir med tiden utsatt för mikrobiell påväxt. När detta ska åtgärdas kallas det sanering vilket innebär att trä rengörs från påväxten, om inte materialet byts ner helt. Oavsett nyproduktion eller befintliga byggnader så säger lagen genom Miljöbalken och Plan- och bygglagen att påväxt som kan orsaka skada eller olägenhet för människors hälsa ska tas bort. Kemikalielagstiftningen betonar att skador som uppkommer så att kemiska produkter och bekämpningsmedel behöver användas ska undvikas om kunskap och tekniker för detta finns. När bekämpningsmedel väl används är det enbart den avsedda användningen enligt instruktionerna som tillåts. Detta gäller allt trä i byggnader där godkännande krävs. Vetenskapliga studier och myndigheter avråder från användning av kemiska medel för att sanera påväxt på trä. Anledningen är att de verkar ha begränsad effekt och att användningen innebär en risk för att det ökar mängden föroreningar i luften inomhus. Dessutom finns en risk att metoderna eventuellt bara dödar den mikrobiella påväxten, utan att den tas bort, och att även död/inaktiv påväxt kan innebära hälsorisker Aktörer inom bygg och företag som sanerar fuktskador efterlyser ett övergripande regelverk och riktlinjer för hantering av fuktskadat trä i byggnader. Sanering av mikrobiella organismer på trä utförs i stor omfattning vid nyproduktion av byggnader om de utsatts för nederbörd eller om skydd mot fukt och vattenskador varit bristfälligt. Fuktsäkerheten behöver prioriteras i större utsträckning i många fall. Redan vid planering av budget och projektering behövs relevanta strategier för att hantera fuktsäkerheten. Áv intervjuerna framgår att slipning av träytor är den vanligast använda saneringsmetoden, följt av isblästring och användning av kemiska medel för att rengöra och bleka virkesytan. Byggnader som utsätts för fritt vatten eller höga fukthalter kan efter längre tid få rötskador och insektskador. Röt- och insektskador, Sammanställningen har finansierats av Svenskt Trä, Trä och Möbelföretagen (TMF) samt RISE.

I denna vägledning beskrivs tre generiska modeller för magasin med låg energiförbrukning. Den största skillnaden mellan detta förhållningssätt till klimatkontroll och konventionell luftkonditionering är att innetemperaturen tillåts följa den yttre årscykeln. Byggnaden är utformad för att ge måttliga variationer i temperatur och relativ luftfuktighet, genom en kombination av värmeisolering, låg ventilationshastighet och byggnadsmaterialens förmåga att lagra värme. Luftfuktigheten styrs av vädermönstret och kombinerar fuktbuffring med vinteruppvärmning eller sommaravfuktning. Konceptet är helt beroende av det lokala utomhusklimatet och fungerar därför endast i tempererade klimatzoner. Tre olika typer av klimatkontroll beskrivs i denna skrift: ouppvärmt magasin med avfuktning, värmebuffring med avfuktning samt skyddsvärme med fuktbuffring.

This guide presents three generic models for museum storage and archives with low energy consumption. The main difference between this simple approach to climate control and conventional air conditioning is that the inside temperature is allowed to follow the outside annual cycle. The building structure is designed to provide moderate variations in temperature and relative humidity, with a combination of low ventilation rate, thermal insulation and thermal mass. The humidity control takes advantage of the weather pattern and combines humidity buffering with winter heating or summer dehumidification. The concept depends entirely on the ambient climatic conditions and therefore only works in temperate climate zones. Three types of climate control are described in this text: unheated storage with dehumidification, temperature buffer with dehumidification and conservation heating with humidity buffer.

This report describes work performed by RISE within Återhus project funded by the Swedish Innovation Agency Vinnova within Challenges-Driven Innovation program. The project aimed for developing new tools for accelerating the transition to circular construction understood as reusing building parts in new buildings. The key part of that process was identified as quality assurance and tackling the challenges concerning legal regulations, certification processes, determination of material quality by non-destructive and destructive testing, as well as calculation of remaining service-life. The report discussed also the most common deterioration mechanisms affecting service-life based on the pilot cases from the project. The calculation tool included carbonation and chloride ingress as two main mechanisms leading to risk of corrosion. Additionally theoretical relation of environment relative humidity to corrosion rate was embedded in the calculation to give an estimate of the remaining propagation period after corrosion initiation. The calculation tools were applied to estimate the residual service-life of slab elements of four pilot buildings based on empirical data gathered during inventory and condition assessment using both non-destructive methods and laboratory testing. A simple classification of concrete elements was proposed with a clear link to three main factors: remaining calculated service-life, observed cracking and the target environment.

As a result of the need for the construction industry to become more and more efficient, this sets new requirements for an increased digitalization of the construction industry as a whole. As consultants are considered a crucial role in the early stages of construction projects, this requires a deeper understanding of the role of consultants in the early stages of construction projects and their further development. Previous studies indicate that increased knowledge and skills can be seen as barriers to further development, mainly in the industry but also in most organizations. This study aims to investigate the barriers that are considered to exist in the Swedish construction industry for increased use of building information modeling (BIM), by highlighting the barriers' links to the HVAC consultant's work and the implementation of knowledge management (KM). This has resulted in the questions 1) What are the barriers to a developed use of BIM in the HVAC industry? and 2) How can KM enable a developed use of BIM in the HVAC industry? The study's theoretical and empirical data collection has consisted of a systematic literature study and semi-structured interviews with plumbing consultants, a supplier, an industry organization and a plumbing expert. The barriers that inhibit a developed use of BIM and adaptation of KM are knowledge and skills, political commitment, unified view of BIM, client's attitude towards BIM, absorptive capacity (ACAP) and culture. The HVAC contractor needs to adapt KM and improve its ACAP in order to increase the level of knowledge within the organization and maintain competitiveness in the market. Adaptation of KM at the HVAC contractor also contributes to an increased level of knowledge in the construction industry as ACAP enables internal and external knowledge sharing. To enable an adaptation of KM, there is a need for a culture that promotes collaboration, trust, learning and the development of BIM in the industry. This requires a cultur, Som en följd av att byggbranschen behöver bli allt mer effektiviserad, ställs nya krav för en ökad digitalisering av byggbranschen i sin helhet. Då konsulter innehar en avgörande roll inom byggprojektets tidigare skeden, krävs en djupare förståelse kring konsultens roll inom de tidigare skeden av byggprojekt samt deras fortsatta utveckling kartläggs. Tidigare studier indikerar att ökad kunskap och kompetens kan ses som barriärer för en fortsatt utveckling, främst inom branschen men även hos merparten av organisationerna. Denna studie syftar till att undersöka de barriärer som finns inom den svenska byggbranschen för ökad användning av building information modelling (BIM), genom att synliggöra barriärernas kopplingar till VVS-konsultens arbete och implementeringen av knowledge management (KM). Detta har resulterat i frågeställningarna 1) Vilka barriärer finns mot en utvecklad användning av BIM i byggbranschen? och 2) Hur kan VVS-konsulten applicera KM för en utvecklad användning av BIM i byggbranschen? Studiens teoretiska- och empiriska datainsamling har bestått av en systematisk litteraturstudie samt semistrukturerade intervjuer. De barriärer som hämmar en utvecklad användning av BIM samt adaptering av KM är kunskap och kompetens, politiskt engagemang, enhetlig syn på BIM, klientens inställning till BIM, absorptionsförmåga (ACAP) och kultur. VVS-konsulten behöver adaptera KM samt förbättra sin ACAP för att höja kunskapsnivån internt inom organisationen samt behålla konkurrenskraft på marknaden. Adaptering av KM hos VVS-konsulten bidrar även till en förhöjd kunskapsnivå inom byggbranschen då ACAP möjliggör för intern samt extern kunskapsdelning. För att möjliggöra en adaptering av KM finns ett behov av en kultur som främjar samarbete, förtroende, lärande samt en utveckling av BIM inom branschen. Därav ställs kravet på en kulturell förändring och ett aktivt ledarskap för att skapa gemensamma normer, en acceptans för nya lösningar, en uppmaning till utveckling, värderi

Digitaliseringen av samhället sker allt snabbare, men till skillnad från de flesta andra branscher så sker digitaliseringen av byggbranschen långsamt. Fastighetsförvaltningen är den del av branschen som ligger mest efter när det kommer till digitalisering. På grund av det har ett informationsgap uppstått mellan projekteringen och förvaltningen. En lösning för att binda samman projekteringens informationsrikedom med förvaltningen kan vara digitala tvillingar. Syftet med denna studie var att bidra till en ökad förståelse kring vad en digital tvilling är och att ge en bättre bild av hur en digital tvilling kan skapas samt hur den kan användas i förvaltningsskedet. Målet var att ta fram en BIM-modell som ska kunna ligga till grund för en digital tvilling som kan användas inom förvaltningen. Den metod som valdes för att undersöka problemet är modellering, där första steget var att ta fram statisk information kring den aktuella fastigheten. Sedan modellerades byggnaden och slutligen tillfördes dynamisk information via en molnbaserad plattform. För modelleringen av byggnaden användes programvaran Autodesk Revit 2023. För att sammanlänka 3D-modellen med den dynamiska informationen användes plattformen Twinfinity. I denna studie har en BIM-modell skapats som utgör en virtuell representation av en verklig fastighet. Relevant statisk och dynamisk information kring fastigheten samlades in och kopplades till den virtuella modellen. Den virtuella modellen som togs fram i denna studie kan per definition inte kallas för en digital tvilling, men kan med vidare arbete utvecklas till en digital tvilling. Den framtagna modellen bör ses som ett bra exempel på hur fastighetsdata kan kopplas till en BIM-modell och på hur informationen kan visualiseras på ett enkelt och lättförståeligt sätt. Resultatet visar att implementering av digitala modeller i fastighetsförvaltningen kan generera fördelar. En digital modell ger fastighetsförvaltaren god kontroll och förståelse kring fastigheten, des, Swedish property management is slow to adapt to the increasing digitalization in society. A tool to help the industry become more digitized is digital twins. The aim of this study is to contribute to an increased understanding of what a digital twin is and to give a better picture of how a digital twin can be produced for property management. The goal is to develop a BIM-model that can form the basis of a digital twin that can be used in property management. The method used to investigate the problem is by modelling an existing building that will be provided with static and dynamic information. The result shows that it is possible to produce a BIM-model relatively easily which can form the basis of a digital twin. The conclusion is that digital models create several advantages for the management, it creates good control and understanding of the property and gathers all information in one place. Currently, there is uncertainty about what a digital twin is due to the lack of an industry-wide definition of the term, which leads to misunderstandings and misconceptions. Lastly, creating a digital twin for an existing property can be problematic as the static information that the digital twin can contain is limited by the amount of information the property manager possesses, as well as the information that can be obtained through a physical examination of the building.

I takt med att den globala befolkningen fortsätter att växa, ökar efterfrågan på nya bostadsbyggnader avsevärt. Samtidigt har behovet av bostäder och byggande vuxit över hela världenunder de senaste decennierna, vilket har lett till en ökad efterfrågan på byggmaterial. Betong ärdet viktigaste byggmaterialet för flervåningsbyggnader pga. sin hållfasthet, men det bidrarbetydligt till utsläppen av växthusgaser. För att minska koldioxidavtrycket och främja hållbarhet är det avgörande att minimera materialanvändning med moderna byggmetoder.Syftet med denna studie är att optimera flervåningsbyggnadsstrukturer genom att ersättabärande väggar med pelare och balkar. Studien använder en referensbyggnad belägen iSandvikens kommun och verktyget StruSoft FEM-Design. Studien genomförs i två steg.I steg 1 utförs modellering, design och analys av referensbyggnaden med bärande väggar(byggnad 1). I steg 2 genomförs en förändring av byggnadsstrukturen genom att ersätta debärande väggarna med pelare och balkar av armerad betong (byggnad 2). Samma procedurersom i steg 1 upprepas för den omkonstruerade strukturen. Resultaten jämförs medreferensbyggnaden med hänsyn till utnyttjandegrad, deformation, spänningar, reaktioner, viktoch stabilitet.Ersättningen av bärande väggar med bärande pelare och balkar av armerad betong har variteffektiv. Båda strukturerna uppfyller de nödvändiga kraven. Baserat på resultaten ärdeformationen 9 mm för byggnad 1 och 7 mm för byggnad 2, vilket indikerar att skillnaden ideformation mellan de två strukturerna inte är signifikant.Byggnad 1 har en maximal utnyttjandegrad på 87%, medan byggnad 2 har en högre maximalutnyttjandegrad på 99%. Detta innebär att byggnad 2 kan utnyttjas i större utsträckning änbyggnad 1. Reaktionskrafterna är 563,6 respektive 476,4 kN i båda byggnaderna, vilketindikerar att reaktionskrafterna i byggnad 2 är 15% lägre än i byggnad 1. Båda strukturerna ärstabila, men det finns en skillnad i byggnadernas totala vikt. Vikterna på byggnaderna

The contemporary imperative of sustainable development has established an unprecedented degree of urgency, in view of the intransigent challenges posed by the persistent and ever-increasing energy and climate crises. In 2019, the Swedish building industry accounted for 21% of the nation’s total greenhouse gas emissions, with the structural framework of a building contributing to 34% of its overall emissions. In response to climate change and the housing demand caused by a growing population, sustainable construction solutions are needed. By substituting steel beams with timber beams, the carbon emissions caused by the building industry can be reduced significantly. This study investigates whether timber based, or steel-reinforced timber beams can provide comparable load-bearing capacity to steel beams while reducing carbon. How this impacts the cross-sectional height of the beams is also taken into consideration. Different load-bearing properties were calculated according to Eurocode using Excel for all the surveyed beams. The carbon emissions were calculated based on the weight of each beam combined with climate data obtained from the Swedish National Board of Housing, Building and Planning. Findings suggest that timber-based beams made from glulam or laminated veneer lumber exhibit moment capacity and bending stiffness on par with those of steel beams while reducing the carbon emissions drastically, but at the cost of increased cross-section height. Steel beams were identified as the main source of carbon emissions. Consequently, also making steelreinforced timber beams only marginally successful in reducing carbon emissions if at all.

I Sverige är det vanligt att använda en träregelstomme för att bygga hus med ett yttretäckande skikt bestående av antingen stående eller liggande panel. Livslängden på panelen ärbegränsad, och när den har uppnått sin fulla livslängd måste den ersättas med ny panel. Dettaär ett betydande projekt som är tidskrävande och kostsamt.Fukt är en viktig faktor som påverkar livslängden hos trä, och den största orsaken tillförkortad livslängd hos trä är biologiska angrepp i form av mögel och röta. Därför ärkunskapen om fuktproblem hos trä av yttersta vikt för att kunna uppskatta livslängden hosolika träkomponenter som används utomhus. Fukt i träpaneler kan också bidra till andrakonsekvenser, till exempel deformationer som bågning och sprickor. När trä blir blöttexpanderar det, och när det torkar krymper det, vilket kan leda till att träets dimensionerändras och att sprickbildning kan uppstå. Detta har visat sig vara en betydande faktor sompåverkar livslängden hos träpanelen.Syftet med denna rapport är att se hur fuktskador uppstår på befintliga byggnader medträfasad samt om det finns skillnader mellan stående och liggande panelers fuktskador.Resultatet visar att det för det mesta sker fuktskador längst ner på fasaderna, vilket beror påatt det är det mest utsatta området på väggen. Dessutom konstaterades att det finns skillnadermellan liggande och stående panel, där den stående panelens fuktskador oftast var merallvarliga längst ner på fasaden, medan den liggande panelen oftast precis som den ståendepanelen hade fuktskador längst ner på väggen men även på övriga ställen på fasaden.Förstudien och experimentet visade på att den stående och liggande panelen är väldigt likavarandra i fuktupptagning och uttorkning. Samt att deras design eller utformning intepåverkar panelens livslängd i någon stor utsträckning. Skillnaden mellan de två paneltypernablir emellertid tydlig när det gäller att byta ut skadade paneler. På en fasad med liggandepaneler är det möjligt att byta ut de nedersta

This study discusses the current state of climate change, which is causing rising sea levels, increasing temperatures, and threatening ecosystems due to human resource exploitation and carbon emissions. The construction industry is a significant contributor to greenhouse gas emissions, and the study aims to investigate which insulation material is best suited for a ground slab in terms of environmental impact, technical properties, and cost. The study includes a literature review and document analysis to compare the technical and environmental properties of different materials, as well as a case study to identify the most suitable material. To make the results comparable, the thickness of the different insulation layers has been chosen in such a way that the U-value becomes equivalent for all construction solutions. This has laid the foundation for the results, which demonstrates what previous research has also found: foamglass exhibits the lowest climate impact because the construction is sufficiently strong without the need for a concrete slab. However, its price is much higher compared to other construction solutions.

The construction industry has increasingly moved in an environmentally conscious direction when energy-efficient and sustainable buildings are in focus. The motivation behind this development is largely about reducing emissions and relieving the environment, both through new construction, but also through making existing buildings more efficient. For that reason, it is relevant to highlight how energy efficiency of existing properties are done, and how it can be optimized from an environmentally conscious perspective. In order to get a clear picture of energy efficiency and its environmental impact, the study will highlight the differences between new production and existing buildings. The parts that will be discussed are economics, sustainability, and the environment. Through qualitative interviews, the largest real estate companies in Skåne will reveal what the work with energy efficiency of existing commercial buildings looks like. Therefore, the purpose of this study is to investigate how the large real estate companies in Skåne work with their existing commercial properties. The method in the study is a qualitative method where people at the property companies had to answer a selection of questions. The questions posed are relevant to modern society and highlight how real estate companies work with environmental factors and economic factors. The result shows that the study of energy efficiency of existing buildings is a crucial aspect of sustainable development. The study deals with the construction and property industry's emissions of greenhouse gases, and it is therefore of the utmost importance to review the existing properties that the property companies own and where there are opportunities for improvement. The improvements are what make existing buildings increase their environmental performance so that they can comply with the environmental requirements that both Sweden and the EU provide. In conclusion, an increased awareness of the benefits of energy

Idag är förseningar inom byggbranschen vanliga och orsakar problem och konsekvenser i byggprojekt. När ett projekt blir försenat uppstår extra kostnader för projektägaren, entreprenören eller båda parter. Med andra ord innebär förseningar ekonomiska förluster och skapar en stressig arbetsmiljö för alla inblandade aktörer och projektmedlemmar. I detta examensarbete identifieras betydande risker som kan orsaka förseningar i projekteringsfasen av byggprocessen, samt presenteras lösningar för att förebygga dem. Byggprocessen består av fyra faser: förstudie, projektering, produktion och överlämning. Projekteringsfasen är ett av de viktigaste stegen i byggprocessen och har stor betydelse för att förebygga förseningar. I denna fas utformas och ritas byggnader, och bygghandlingar tas fram med konstruktionsritningar, tekniska lösningar och beskrivningar upprättas för att styra hela byggprocessen. Detta arbete fokuserar på förseningar i själva projekteringsfasen och dess påverkan på hela projektet, samt hur de kan förebyggas. Arbetet består av en teoretisk och en praktisk del. Syftet med arbetet är att undersöka orsakerna till förseningar inom projekteringsfasen och att hantera dem på bästa sätt genom att utveckla riskhanteringen. Orsakerna kan vara ofullständig information, förändringar i projektspecifikationer och tekniska problem. Teorin bygger på litteratur om projektering i byggprocessen för att ge en bred kunskapsbas om projektering innan den praktiska delen genomförs. Den praktiska delen baseras på intervjuer med erfarna projektledare inom projektering som har varit involverade i olika försenade projekteringsprocesser. Resultatet presenterar projektledarens svar angående orsakerna till förseningarna i de två projekten. I diskussionen jämförs och analyseras resultaten med teorin, vilket visar att sjukdomar och bristande kommunikation, tillsammans med andra risker, kan vara orsaker till förseningar i projekteringsfasen. Förbättringsförslag inkluderar att skapa en trygg o

In Sweden, more buildings are being built today than ever before, while awareness of the consequences this has for the climate has increased. On January 1, 2022, a law came into effect to introduce climate declarations for new constructions. This is one step towards becoming a country that will have net zero emissions by 2045. To further develop the law, Boverket has developed a proposal to introduce limit values in climate declarations, which will apply from 2027. The introduction of limits will affect the construction industry as the future buildings will need to be built differently than they are today to meet the requirements. This project aims to contribute knowledge in sustainability to reduce emissions in the construction industry. Furthermore, to provide suggestions for changes in a building's construction to meet the future limits. The building in this project is to symbolize a typical apartment building in Sweden. It has been modeled in the software Revit and then been exported to the Carbon Cost Compass software, where different examples of the building have been created, with differences in material choices. This while maintaining the average thermal transmittance, Um, as to not affect the building's insulation capacity. The result of the climatic action in the original building was 396.1 kg CO2e/m2BTA according to the requirements for 2027, in comparison with the limit value which was calculated to be 257-294 kg CO2e/m2BTA. Four different versions of the building were created with suggestions for changes in the construction, to meet the limit values. The version of the building with the lowest emission is the one referred to as "Minimum", with a climate action of 160.1 CO2e/m2BTA. In May 2023, Boverket released an updated proposal regarding the expansion of climate declaration laws. The proposal presents initial threshold values for various building types, including apartment buildings. The suggested limit of 375 kg CO2e/m2BTA is planned to be impleme, I Sverige byggs det idag mer än vad det någonsin gjorts tidigare, samtidigt som vetskapen om vilka konsekvenser detta har för klimatet blivit större. Den 1 januari 2022 trädde lagen i kraft om att införa klimatdeklarationer för nybyggnationer i Sverige. Detta är ett steg på vägen mot ett land som ska ha netto noll utsläpp 2045. För att vidareutveckla lagen har Boverket tagit fram ett förslag om att införa gränsvärden i klimatdeklarationer, som ska börja gälla 2027. Införandet av gränsvärden kommer påverka byggbranschen då framtidens byggnader behöver byggas annorlunda än vad de görs idag, för att kunna möta klimatkraven. Detta arbete syftar till att bidra med kunskap inom hållbarhet, för att på sikt få ner utsläppen i byggbranschen. Vidare att ge förslag på förändringar i en byggnads konstruktion för att klara Boverkets framtida gränsvärden. Byggnaden i arbetet ska symbolisera ett typiskt flerbostadshus i Sverige, som modellerats upp i programvaran Revit. Denna har sedan exporterats till programvaran Carbon Cost Compass, där olika varianter av byggnaden har skapats, med skillnader i materialval. Detta har gjorts med bibehållen genomsnittlig värmegenomgångskoefficient i byggnaden, Um, för att inte påverka byggnadens isoleringsförmåga. Resultatet av klimatberäkningen i det ursprungliga flerbostadshuset blev 396,1 kg CO2e/m2BTA enligt kraven för 2027, i jämförelse med gränsvärdet som beräknades ligga på 257–294 kg CO2e/m2BTA. Det skapades fyra olika versioner av byggnaden där förslag av förändringar i konstruktionen presenterades för att byggnaden skulle klara gränsvärdena. Den version av byggnad som hade minst utsläpp är den som i rapporten kallas för ’’Minimum’’, med ett klimatutsläpp på 160,1 CO2e/m2BTA. I maj 2023 kom Boverket ut med ett uppdaterat förslag på hur de ska vidareutveckla lagen om klimatdeklarationer. I förslaget framgår preliminära gränsvärden för olika byggnadstyper , däribland flerbostadshus. Gränsvärdet på 375 kg Co2e/m2BTA föreslås träda i kra