The Netherlands faces an urgent housing shortage, especially in urban areas where demand outpaces supply and space for new development is limited. Modular construction presents a scalable and efficient solution, yet its application in mid-rise buildings up to 70 metres remains constrained by unresolved structural challenges, particularly regarding lateral stability, connection behaviour, and collective module behaviour. Previous research acknowledged the individual potential of outrigger elements and tie-rod connections to enhance stability, but their combined integration in a modular mid-rise context had not yet been fully explored.

This thesis addresses that gap by developing, analysing, and validating a hybrid structural concept in which corner-supported steel modules actively contribute to the building’s lateral load resistance. The proposed system integrates tie-rods and steel outriggers with a precast concrete core to transform the modular units from passive vertical load carriers into active components of the lateral stability system. To assess this system, a four-phase research strategy was adopted, including a feasibility study, concept development, structural optimisation, and a final 3D case-study application. A key methodological decision was the use of parametric modelling tools, Grasshopper and Karamba3D, to enable rapid iteration and flexible structural analysis across design alternatives.

The analysis demonstrated that, in a 20-storey structure, the integration of two outrigger levels (floors 7 and 14) reduced top displacement by 13.5% compared to a core-only structure. The structure reached a height of 67.7 m while satisfying the H/750 serviceability criterion. Member utilisation levels remained below 1.0, and tie-rod forces stayed within feasible limits. However, the effectiveness of the proposed concept was significantly influenced by axial elongation of the tie-rods: M24 tie-rods reduced outrigger effectiveness to 17.7% compared to 25.4% in the idealised case without elongation, while M50 tie-rods improved performance to 20.5%. Parametric studies further showed that outrigger effectiveness depends strongly on the stiffness of the concrete core. With a flexible core, outriggers reduced lateral displacements by over 30%; this benefit dropped below 10% for stiffer configurations, underscoring the importance of a balanced stiffness distribution between core and outriggers to maximise the effectiveness of the proposed concept.

These findings demonstrate that the proposed hybrid concept is a viable solution for modular mid-rise construction, enabling greater design heights while maintaining structural efficiency. The innovative use of parametric modelling not only enhanced design flexibility but also accelerated the evaluation process. The research contributes a validated structural concept that addresses current limitations in modular design and provides a foundation for further innovation in hybrid modular systems.

Point-supported Cross-Laminated Timber (CLT) floor systems offer architectural flexibility and material efficiency, enabling biaxial load transfer while minimizing reliance on traditional post-and-beam structures. However, the structural integrity of such systems is highly dependent on the design and performance of panel-to-panel and panel-to-column connections. This study examines these panel-to-panel connections through a comprehensive numerical modelling approach, evaluating both static and dynamic behaviour to inform early-stage design decisions.

To assess static behaviour, a bending moment estimation formula is developed, allowing engineers to approximate internal forces in panel joints without requiring extensive finite element simulations. This facilitates efficient preliminary design calculations for structural connections, emphasizing the crucial role of rotational stiffness at line hinges. The analysis demonstrates that actual bending moments transferred can be significantly lower than those assuming rigid continuity, particularly for connections with moderate to low stiffness. A unified reduction factor, derived from parametric studies, enables practical and reliable estimation of bending moments across various floor configurations.

For dynamic behaviour, vibrational performance is analysed using parametric simulations based on the HIVOSS methodology, revealing the interaction between connection stiffness, flexural stiffness and stiffness ratios on modal response characteristics. The findings underscore the importance of ensuring adequate connection stiffness to maintain floor vibration comfort and serviceability. Design graphs constructed from these simulations provide engineers with intuitive tools to evaluate vibrational performance and assess serviceability thresholds prior to detailed modelling.

The proposed splice plate connection with inclined screws is subjected to analytical and numerical validation using Python-based mechanical models and RFEM finite element (FE) simulations. Key design rules were established to optimize screw length and panel height. While the current models adequately support early-stage design, further refinement, particularly in modelling compressive force dispersion within lamellas could improve accuracy in predicting bending capacity.

A comparative case study between point-supported and conventional beam-supported CLT floor systems highlights architectural and structural trade-offs. The point-supported system offers increased free height and simplified structural layouts by eliminating continuous beams, which benefits architectural integration. However, these advantages come with increased timber volumes and more complex point and panel-to-panel connections requiring detailed engineering. Both systems can satisfy strength and serviceability demands, but the choice depends on project-specific priorities such as spatial efficiency, material availability and construction complexity.

The findings contribute to the development of design guidelines that bridge the gap between theoretical feasibility and practical implementation. By providing engineers with simplified estimation tools and validated numerical insights, this research aims to facilitate the broader adoption of point-supported CLT floors in modern day timber construction.

This research contributes practical design guidelines bridging theoretical modelling and real-world application. By providing simplified estimation tools, validated numerical insights and design aids for both static and dynamic performance, the study facilitates the broader adoption of point-supported CLT floors in modern timber construction.

The design of 2D rectangular steel trusses demands a critical balance between structural performance and constructability, a core challenge in civil engineering. Using distinct cross-sectional profiles minimizes material use but elevates structural complexity, whereas standardized profiles facilitate construction simplicity at the cost of efficiency. This thesis develops a multi-objective optimization framework to navigate these trade-offs, targeting four essential objectives: mass minimization to reduce material requirements, connection degree to simplify joint configurations, symmetry to enhance aesthetics and standardization, and beam continuity to streamline assembly processes. By controlling the number of unique HEA profiles, the study delivers tailored solutions for preliminary structural design, aligning with engineering priorities and stakeholder preferences to optimize truss performance and practicality.
A computational framework employs the Tree-structured Parzen Estimator (TPE), a sample-efficient Bayesian optimization method, to efficiently explore the complex, discrete design space of truss configurations. TPE performance is rigorously validated against exhaustive search (EXS) to ensure accuracy in identifying optimal designs. Stakeholder-defined weights, implemented through weighted scalarization, enable customized trade-off analyses, though without direct stakeholder engagement. This approach supports the exploration of diverse configurations, effectively balancing performance and standardization while addressing the computational demands of large search spaces, thus providing a robust tool for 2D truss optimization.
The findings indicate that intermediate profile grouping often produces designs that balance structural performance and constructability. The multi-parallel plot, a dynamic visualization tool, potentially empowers stakeholders, including engineers and project managers to transparently explore trade-offs, pending practical validation. Despite limitations, such as untuned TPE hyperparameters and a focus on 2D trusses, this promising framework enhances transparency and adaptability in preliminary structural design. By integrating efficient optimization with intuitive visualization, the study establishes a foundation for future advancements in steel truss optimization, offering a versatile methodology with potential to inform broader structural engineering applications.

The increasing demand for sustainable and high-rise buildings has led to the development of hybrid concrete-timber structures. These buildings incorporate a concrete core and columns for stability, combined with timber and concrete floor systems, providing an opportunity to balance sustainability, structural efficiency, and cost-effectiveness. While this approach presents opportunities, it also introduces several challenges related to structural dynamics, fire safety, environmental impact, and construction costs.

A key issue in concrete-timber hybrid buildings is their lower weight due to timber floors that are lighter than concrete floors, which makes them more susceptible to wind-induced vibrations. Additionally, the irregular mass distribution caused by alternating timber and concrete floors over the height of the building influences the dynamic response of the building. From an environmental perspective, timber is often regarded as a sustainable material due to its carbon storage capability. However, the extent to which hybrid systems reduce overall carbon emissions compared to concrete buildings remains uncertain. Furthermore, construction costs are closely tied to structural and environmental performance, impacting the feasibility of such buildings.

Despite growing interest in hybrid concrete-timber high-rises, existing research lacks an integrated approach that examines the relationships between dynamic behavior, environmental impact, and construction cost. Although individual aspects have been studied, the correlation between these design factors remains unclear. Additionally, the influence of parameters such as building height, floor type, and concrete-timber distribution on these design aspects has not been extensively explored.

This research aims to support the integral design of hybrid concrete-timber high-rises by offering a structured approach to evaluating key design choices and their implications. The findings contribute to a more holistic approach to hybrid building design, supporting designers, policymakers, and researchers in optimizing hybrid systems.

This thesis explores the influence of key building parameters on the design aspects of tall concrete-timber buildings during the early design phase. The goal is to identify relationships between dynamic behavior, environmental performance, and building cost by analyzing various building variants. The studied parameters include building height, floor plan, floor type, and the percentage of concrete floors. To achieve this, three hypotheses are formulated that connect the design aspects with the percentage of concrete floors. By analyzing different percentage of concrete in the floor systems, the study aims to provide insights into the complex interactions between these aspects.

The methodology consists of three parts. First, building variants are designed based on predefined parameters, using structural calculations for floor systems, concrete cores, and foundations. Second, models are developed to determine the dependent variables: dynamic behavior (first natural frequency), environmental performance (Environmental Cost Index through Life Cycle Assessment), and construction cost. Based on the results of the models relationships between independent and dependent variables are analyzed to identify trends and interactions. Finally, correlations between the three design aspects are examined to provide insights into their interdependencies.

The results indicate that building height is the most significant factor influencing dynamic behavior, environmental performance, and construction cost. This is evident from the distinct scatter plots for each building height. The ECI value for buildings between 70 and 90m ranges from 12 to 28 €/m², while for buildings of 110m, it ranges from 20 to 33 €/m². Construction costs for buildings between 70 and 90m range from 735 to 875 €/m², and between 850 and 1000 €/m² for buildings of 110m. By analyzing the results, no significant correlation between construction cost and other parameters was found, as the effect ranges of the parameters are similar. Moreover, the dynamic behavior of the buildings remains within safe limits. Additionally, variations in foundation piles and core dimensions significantly impact the environmental cost index (ECI) and construction cost, making their inclusion essential for accurate comparisons. Finally, the model effectively analyzes specific parameters, thereby providing clear insights into their influence on design aspects.

The increasing demand for sustainable and easily constructible housing has led to the exploration of alternative foundation systems for lightweight modular structures. This research investigates the feasibility of using short helical piles to support a lightweight wooden building, assessing its settlement behaviour and structural integrity over time. Unlike traditional deep pile foundations, short helical piles are designed to be easily installed, removed, and reused, offering both environmental and economic advantages. However, their application in soft soils raises concerns regarding excessive and differential settlement.

The main research question for this thesis is:
”What is the structural feasibility of a lightweight, modular wooden building design on short, screwed foundation piles that is expected to have large amount of settlement?”
To answer this question, a literature study was done in combination with a case study. The literature established the boundary conditions for the use of helical foundation piles and explores the expected capacity and settlement behaviour in soft soil. Afterwards, it focusses on aspects such as decay and modular systems of timber construction elements.
With the knowledge obtained from the literature, a case study was developed. To investigate the behaviour of a lightweight structure that is expected to settle, a numerical modelling approach is used, combining PLAXIS 2D and SCIA Engineer. PLAXIS 2D was used for simulating the settlement behaviour of the structure at multiple stages in time, while the effect of these settlements on the superstructure was analysed in SCIA Engineer. Different wall systems were investigated, focusing on the influence of the wall stiffness, varying pile capacities, and the impact of uneven loading. Time-dependent settlement effects were evaluated at time stages just after the completion of the construction and at three additional points further in time. This provides insight on the short-term and long-term behaviour of the structure. To prove that a structure of this typology is sufficient for housing, it is tested on total settlement (𝑈), differential rotations (𝛽), tilt (𝜔), and element capacity (𝜎).

The results of the calculations indicate that for a lightweight, timber structure placed on short helical piles large amount of settlement can be expected when positioned in soft soil. However, the settlements will not lead to a significant stress increase that causes failure of structural elements. A stiffer wall system has the ability to redistribute more force to the foundation piles at the most outer position. This reduces the differential settlement between piles, but also reduces the maximum total settlement of the wall. The resistance to deformations of the outer foundation piles is therefore more impactful with a stiffer superstructure. In general, the findings suggest that with careful consideration of settlement behaviour, short helical piles can be a viable foundation solution for supporting lightweight houses.

The construction sector aims to reduce its environmental footprint to address climate change and material depletion, with an increasing focus on reducing embodied carbon. Simultaneously, there is a growing demand for affordable housing in the Netherlands. A significant part of the new housing stock needs to be mid-rise residential, efficient in both material and land use. Bio-based materials, such as timber, which are renewable and have relatively low carbon emissions, could play a key role in reducing embodied carbon for these types of buildings. Since structural systems often account for the majority of a building’s embodied carbon, using timber here can offer significant advantages. However, its application in practice remains relatively uncommon in the Netherlands.

Although existing research highlights the potential of timber in structural systems, challenges such as limited knowledge, lack of incentive and financial barriers are often cited as key reasons for its limited adoption. This research aims to address these challenges by exploring and quantifying to what extent a shift toward timber-based structural systems can reduce the environmental footprint of mid-rise residential buildings in the Netherlands, while maintaining economic feasibility. By doing so, this research aims to offer practical insights into the use of timber in construction, addressing knowledge gaps and identifying the conditions for its application in practice.

A comprehensive literature review was conducted on environmental regulations, assessment methods, structural systems, and suitable compositions of structural elements using timber. The insights gathered were applied to a case study, where various redesigns were developed and optimised under different boundary conditions. The environmental impact was quantified by a life cycle assessment using the Paris Proof Indicator (PPI, measured in GWP-GHG). Simultaneously, economic feasibility was quantified by an evaluation of construction costs. The scope of the assessments is limited to the life cycle stages from cradle to practical completion, emphasising the importance of direct impact.

As a result of the assessment of the case-study redesigns, several building concepts provided significant reductions in environmental footprint while being economically feasible. Compared to the original design, hybrid redesign concepts with calcium silicate brick walls and CLT-concrete composite floors can achieve PPI reductions up to 42% while being of equal or lower costs. Concepts with CLT walls and hollow core timber floors can even lead to reductions of PPI up to 55%. Within a 10% increase in costs, a wider range of concepts can lead to similar PPI reductions. All concepts with both CLT walls and CLT floors proved to be economically unfeasible within the stated cost thresholds.

The associated PPI values were found within the range of 82 and 114 kg CO2-eq./m², depending on the building concept. Accounting for design variations between mid-rise residential buildings, research uncertainties, and potential design optimisations, the building concepts researched could align with the Paris Agreement targets up to 2035. As the targets for 2050 are roughly twice as strict, it is unlikely that these are achievable within the researched design strategies. Incorporating reused or recycled materials and/or accounting for the benefits of temporary carbon storage in bio-based materials will likely be necessary to achieve these targets.

Parametric tools could significantly increase efficiency in the design process within the construction industry, especially with prefabricated elements. Efficiency is also searched for in material use. An element that uses its material very effectively is a structural insulated panel (SIP). However, the synthetic polymers used in already existing panels are not very sustainable. The new climate agreements push producers into making more sustainable choices. Due to this, Kingspan Unidek is experimenting with a bio-based insulation material integration into the SIP. A new structural insulated panel with OSB/3 faces and a Steico wood fibre polyurethane resin insulation core is being developed. In this thesis, the panel’s behaviour is analysed for construction purposes under axial and transverse loading experimentally, analytically and through modelling. The behaviour of the panel is analysed for residential building applications, and the possibility of using parametric modelling tools in the design process for SIPs is assessed.
The analysis is performed by using four main methods – full-scale experiments under eccentric axial loading by Kingspan, models on Karamba3D and RFEM, and analytical calculations with Timoshenko beam theory, shear beam equations and rod in compression equations. The failure methods are analysed with hand calculations from sandwich panel theory. The Karamba3D model is developed by using shell and beam elements since it is not yet possible to model layered materials. The material is defined by the user and the core is modelled as beams which are scaled to match the Timoshenko beam equation results.
The faces exhibited a separate behaviour during the experiments under low eccentric axial loads suggesting a delamination failure or a core failure. The failure occurred during an eccentric 18 kN/m axial loading which caused the faces to behave separately. The core has very low strength properties compared to other conventionally used SIP insulation materials which are at least twice as strong as the Steico insulation board. Additionally, the analytical calculations showed that the panel has very low transverse loading capacity as a result of core shear failure – a maximum distributed load between 0.1 kN/m to 2.5 kN/m can be applied depending on the analysis method. These findings confirm that the panel could only be used with the application of through-thickness stiffeners. The developed Karamba3D model successfully reproduced the experimental results, but the model should not be used for failure analysis since local failures or interface failure is not described. Timoshenko beam theory and the RFEM model showed a good correspondence for transverse loading, but a bending test should be performed to confirm the results. The RFEM model could not show the SIP behaviour under axial loading but did exhibit a trend in deflection results towards where a local failure could occur. The conventional sandwich panel theory overestimated the panel resistance based on the experimental results and the modelling results.
The panel in this form could only be applied if through-thickness stiffeners are used to strengthen the panel or if the core material is significantly improved. However, there is a possibility that the separate behaviour by the faces could be avoided by avoiding eccentric loading and only applying centric loading. It would be necessary to test the panel for failure to get a better understanding of the failure modes and to further validate the model values. Additional testing to confirm the failure method would be testing the material properties of the Steico material, and the bond strength of the interface between the faces and the core. The model has the potential to be used for analysing all different sandwich structures, but would need to be further verified with different materials.

Converged solar reflection resulting from the curved façades of mid-rise and high-rise buildings has proven to be a uniquely dangerous phenomenon, yet increasingly common. The "death ray" incident at 20 Fenchurch St (the "Walkie Talkie" Building) in London in 2013 was mirrored by a similar occurrence at the Amsterdam University Medical Center (AMC) in 2021, where parts of a car melted from the intense heat produced. This reoccurrence raises a fundamental question as to why this problem keep happening. Several factors may contribute: past studies focused on isolated instances, many building engineers and architects are unaware of the risks, and numerical reproduction of this phenomenon involves numerous parameters and complex scripting.
This thesis aims to provide an algorithm to accurately reconstruct the converged solar reflection phenomenon numerically by analyzing various input parameters, such as the geometry of a façade, the nonlinear reflection rate of glass panels, and the effect of anisotropic sky models. To ensure the validity of the model, on-site solar irradiance measurements were conducted in the parking lot of the AMC building. Additionally, the program was used to reenact the phenomenon at the Walkie Talkie building before improvements to its façade.
Results indicate that the three-dimensional problem can initially be approached with a two-dimensional model using horizontal cross-sections of the façade. The angles at which the most intense focal points occur in both the 3D and 2D models of the AMC building correspond to each other, at 15.24 and 23.04 degrees from the optical axis of the façade (solar azimuth angles of 147.34 and 139.54 degrees from the north). The study also concludes that under the same conditions, replacing a quarter-circle-shaped curved façade with a parabolic-shaped curved façade would significantly worsen the effect, potentially leading to five times higher converged solar reflection on the ground.
In the case of the AMC building, the highest recorded irradiance during measurement was 4834 W/m². This value differed by only 13.45% from the 3D model using the Reindl sky model, which showed 4184 W/m². Conversely, the conventional isotropic sky model produced a larger difference of 23.68%. For the 20 Fenchurch St building, the Reindl sky model also produced more intense results compared to the isotropic model, with the focal point intensity reaching up to 6271 W/m² on August 29, 2013. However, limited access to accurate three-dimensional models and details of the surrounding area may have affected the results.
The study also examined the systematic error due to mismatched curvature of the glass panels with the building's curvature. This mismatch caused irradiance variations, increasing by up to 23.52% at one time and decreasing by 13.09% at another, indicating no constant increase or decrease on the intensity of the focal point.
In conclusion, this thesis successfully captures various variable inputs to recreate an accurate converged solar reflection phenomenon in both the AMC and the "Walkie Talkie" buildings. It integrates these variables into one continuous script without the need to switch between different software, providing a comprehensive tool for assessing and mitigating this dangerous architectural flaw.

The museum Boijmans van Beuningen in Rotterdam is currently closed for restoration. The architect Van der Steur made an extensive study of lighting in museum rooms (1930). This resulted in a pitched roof with glass and a layer of horizontal glass panes (legramen) that form the ceiling of the exhibition rooms. Below the glass panes timber blades (schoepen) are placed under an angle to disperse the light.
The museum board wants to preserve the vision on daylight of Van der Steur and is now considering options for sun shading above the ceiling. This addition will allow them to better control the illumination in the museum and protect the artwork.

This Master thesis describes a method to assess the daylight exposure in the museum Boijmans van Beuningen. It can be used for a combined lighting design (daylight and artificial). The purpose of the method is to compare different sun shading solutions and their effects on the illuminance. A toolbox is made that can be used on other museums.

The method starts with a 3D model of one of the museum rooms. Alterations had to be made to accommodate the temporary renovation state. For the validation of the model, HDR images were made on-site. These results were compared with the calculation made with the 3D model. Iteratively the best possible fit was made.

With the validated model an hourly daylight simulation was done using the EPW climate-based weather data. The resulting illuminance exceeded the desired level at several points in time. Three different types of sunscreens were chosen. These were schematised as a continuous layer on top of the legramen. Based on the behaviour of the sun shading on three specific days, a daylight factor of 2% was found between the illuminance on the wall and the outside illuminance. With this relation and the EPW weather data the desired sun shading states for an entire year are predicted. A control mechanism is designed for the opening and closing of the sun shading based on local measurements. When the sun shading state changes, the illuminance can fall below the desired level of 125 lx. In that case, additional artificial lighting is needed. The calculations show that over an entire year, the total exposure is 469.286 lx·hr, this is a reduction of 82.2 % compared to the museum without any sun shading.

With the developed approach the user can gather building-specific characteristics and geometries, that include some form of ‘device’ that controls the top light entering a room. If the first part of the modelling process is done, and the hourly data is collected, the model behaves within the practically accepted limits that were set. This version can assess what selection of screens is effective, that will reduce the incoming light, without unnecessarily over-reducing it, and so limits the need for additional diffuse artificial lighting.

This research investigates the effect of window position and size on building facades on daylight entry, energy consumption, and thermal comfort of buildings. The aim is to find a feasible way to make housing more sustainable and energy efficient in compliance with the Dutch Building Regulations while providing good daylit spaces. This knowledge can be helpful to architects and engineers at an early stage in the design process who intend to design a sustainable building. This research is done in relation to the graduation from the TU Delft Building Engineering Master's degree in cooperation with the company Sweco Nederland B.V. located in De Bilt.
This study developed a parametric model based on the NTA 8800 calculation method for energy demand and the NEN-EN 17037 daylight norm. Two different types of reference building are investigated, a middle apartment in an apartment building and a middle terraced house. The parameters used for this study are the orientation of the building, the height and width of the window (and therefore WWR), as well as vertical and horizontal positioning of the windows, and a balcony cantilever in front of the apartment windows. The results show that:
The lower WWR boundaries are independent of orientation, and therefore, the minimum WWR values per orientation are the same. The lower boundary of the apartment (33%) is strongly influenced by the present overhangs, while the terraced housing requires a minimum WWR of 12%. The results show that the maximum WWR for terraced housing is mostly restricted by the BENG1 requirement (25% -38%), except for the south orientation (36%) which is limited by TOjuli. The maximum WWR of the apartment is restricted mainly by TOjuli (33% - 60%). The BENG1 results show that a north-south orientation for terraced housing is best to minimise energy demand (WWRs of around 38% are possible until requirements are exceeded). For the geometries studied, this research suggests a WWR for an apartment building roughly between 30% and 45% and for terraced housing roughly between 13% and 25% as a starting point. On top of that, it is recommended to install windows in the middle of a facade in terms of horizontal position and in the upper part of the facade in terms of vertical position to maximise daylight entry. Glass below the reference surface height of 0.85m should be avoided.
The results of this research indicate certain guidelines, rules, and statements that can be used when working with the new regulations, of which the most fundamental statement: As a consequence of the updated daylight standard from NEN 2057 to NEN-EN 17037, an increase in WWR no longer directly leads to a higher daylight factor, as it did under the current regulation.
Furthermore, this study reveals clearly that despite the fact that energy demand and daylight are theoretically closely related, regulations are separated more. Daylight and energy demand are better separable (and individually optimised) in regulations than expected beforehand.
The methodology used demonstrates its robustness and practicality in analysing complex problems and obtaining validated results. Therefore, the methodology used can be recommended for further research and larger design projects in practice.

The building industry is the largest global contributor to carbon emissions. At the current rate of carbon emissions within this sector, the targets set by the Paris Agreement will not be achieved. Consequently, significant reductions in carbon emissions from the building industry are needed to align with global climate goals.

When discussing the carbon emission of a building two major type of carbon emissions can be distinguished: 1)operational 2)embodied. Operational carbon is all the CO_2 that is emitted during the use of the building and refers to the energy-related carbon emissions. Embodied carbon is all the CO_2 that was emitted to realize the construction of the building.

Historically, sustainable building design has focused on reducing operational carbon. However, as improvement in low-energy buildings continue to decrease operational emissions, the significance of Embodied Carbon has grown. Despite this, Embodied Carbon remains underrepresented in the design process, often addressed reactively at the end of the design, leading to unnecessarily high levels. Embodied Carbon must be integrated in the early design stages to create buildings with a low Embodied Carbon content, improving the sustainability of the building industry.

This master thesis introduces a parametric framework designed to embed Embodied Carbon assessment into the early building design process. Recognizing the uncertainties inherent in early design phases the framework prioritizes delivering ranges of values rather than precise figures, befitting of the dynamic and flexible nature of design exploration. By offering quick, clear results and transparent methodologies, the framework stimulates a multidisciplinary workflows, enabling accessible, efficient, and informed decision-making without requiring specialized expertise.

The framework consists of three tools; 1)Structure Generator Tool: Translates design parameters into structural systems and material quantities without requiring specialized engineering knowledge. 2)Embodied Carbon Material Factor Determination Tool: Converts material quantities into Embodied Carbon values using databases, with the flexibility to include or exclude biogenic carbon storage. 3)Iterator and Data Evaluation Tool: Supports iterative design exploration, comparing design alternatives and facilitating clear visualization and communication of results through tools like DesignExplorer.

The developed framework effectively supports the early design stage by providing actionable insights, enabling designers to quantify the impact of their choices with ease and efficiency. By integrating multidisciplinary variables, default settings, and automated element generation, the framework stimulates a multidisciplinary collaboration without requiring, but allowing the application of, specialist expertise. A range-based approach accounts for uncertainties in Environmental Product Declaration (EPD) selection, while sensitivity analyses helps distinguish robust conclusions from those sensitive to design changes and allowing the converging of the carbon assessment throughout the design process. Although future refinements,such as improved connection design and substructure integration, could enhance accuracy, the framework already delivers reliable estimates for Embodied Carbon assessment. Comparisons of databases show slightly conservative results for the Dutch building industry when using ICE V3.0 instead of NMD. Overall, the framework lays a strong foundation for integrating Embodied Carbon considerations into early design, proving its potential to significantly reduce carbon emissions in building practices.

Based on previous studies, the Dutch Building Regulation (BBL) is inadequately equipped to address fire safety in timber-structured buildings, particularly when the timber is exposed and in the context of tall buildings. Fire compartments containing large volumes of structural timber suffer from additional fire safety risks compared to traditional buildings without a combustible structure. These extra risks include: a longer fire duration, unpredictable fire scenario, potential second flash-over, failure of timber members due to heat wave-penetration, larger protruding flames from openings and increased smoke production (Brandon et al., 2022). This master thesis focuses on studying fire safety of CLT (Cross Laminated Timber) compartments with properties typical for apartment buildings. The master thesis contains a literature study, divided into material level, structural component level, compartment level and building level. This literature study can be helpful for people who want to understand the fundamentals of fire safety in contemporary CLT timber buildings and want to understand the further master thesis with more ease.
In this master thesis we used three fire behaviour models to analyse compartment fires previously tested in full scale by Brandon et al. (2021a). The outcomes of simulations done with these models were compared to full-scale compartment fire test data (for a compartment of 48 square meters) to get an understanding of the accuracy, and strengths and weaknesses of the models. The study suggests that the ZHM and Brandon models are able to simulate the average char depth in the ceiling. For compartments that have percentage of exposed mass timber and an opening factor equal to that in test 1 of Brandon et al. (2021a), the outcomes of the Brandon and the ZHM models give conservative results for the the maximum char depth in the ceiling. There is a discrepancy between the simulation results and the maximum char depth in the walls when amount of exposed timber and opening factor were increased beyond the values used in test 1 of Brandon et al. (2021a). Suggestions for correction factors based on linear interpolation are given to arrive at a better approximation for the maximum char depth. It is advised to use CFD and/or compartment fire tests for any compartments that differ from tests 1-5 in Brandon et al. (2021a). Targeted design measures were listed to protect the critical areas where maximum char depth is expected.
In order to get a better understanding of the fire behavior models for CLT compartments, I simulated 24 different realistic compartments, with differing sizes, shapes, amounts of exposed timber and opening factors. The parameters were chosen in such a way, that the variations encompass a range of typical CLT apartment buildings. I performed this analysis using three different fire behaviour models. The models calculate the charring depth into the CLT cross-section. We then added the zero strength layer (timber without any structural resistance due to the heat-wave) to the modelled charring depth, resulting in the effective char depth. The larger the effective char depth, the more of the cross-section’s initial resistance is lost. Over the three models, the largest correlation was found to be between opening factor and effective depth. The second largest correlation was found to be between amount of exposed timber and effective depth. Using the results of the models, without any correction for maximum char depth, none of the simulated compartments suffer failure of the ceiling panel according to calculation.
Between the three models, the zone model (Brandon et al., 2021b), is best capable of simulating protection for a finite number of minutes, as the exact number and thickness of the protection can be input in the model.

Since its emergence in 2008, blockchain technology has significantly expanded its scope, impacting various industries beyond its initial cryptocurrency applications. Its potential to enhance established practices is increasingly recognized, yet its application in the Architecture, Engineering, and Construction (AEC) industry has been relatively little researched to date, let alone been applied in practice. This research aims to develop a system facilitating the initiation and management of architectural projects on the blockchain, enabling multi-disciplinary collaboration and participation, by integrating blockchain technology into the AEC ecosystem. The proposed system is designed to allow architects, engineers, and designers, irrespective of their preferred design software, to contribute, manage and record their designs. By uploading these designs to the InterPlanetary File System (IPFS) and recording the IPFS hashes on the Ethereum blockchain, the system ensures immutable data provenance, transparent ownership representation, and heightened project transparency. Furthermore, this framework automates various aspects of project management, including contractual obligations, payments, and compliance verification through smart contracts. At the core of this research is a multi-step approach that begins with a literature review to establish the current state of blockchain applications within the AEC sector. The review focuses particularly on the potential of smart contracts, NFTs, and IPFS for improving the management of construction projects. A conceptual framework is then developed, drawing from the literature to designing a prototype system that integrates these technologies. The prototyping phase involves creating a blockchain-based system where architectural project management can be conducted securely and efficiently. Key to this phase is the crafting of smart contracts to automate project workflows and the use of NFTs for clear delineation of design ownership and achievements. The system also incorporates a method for offchain storage of design files through IPFS, connected to the blockchain, ensuring data integrity and easy retrieval. Systematic testing under certain scenario assesses performance and informs iterative optimization to refine the system's functionality. A performance evaluation strategy is employed to assess the prototype, ensuring its suitability for real-world applications in the AEC sector. This research develops a blockchain-based system in attempt to restructure project management in the AEC sector. Through iterative development, testing, and optimization, the objective of this study is to contribute to enhanced efficiency, transparency, and collaboration within the industry, exploring the potential benefits of integrating blockchain technology in a structured and measured manner.

The circular potential of existing aluminium curtain wall facades is investigated in this study. The focus is primarily on reuse, refurbishment and re-manufacturing, aiming to raise the value of materials that have not yet reached the end of their service life. The increasing concern about resource depletion, damage to the ecosphere and the need for sustainable development increases the demand for sustainable strategies in many industries. The building industry is one of the most polluting industries at current times and with governments incorporating laws regarding these topics, the need for methods to reduce the impact in this industry is needed. Facades have a great impact on the whole life carbon impact of a building and show potential for reuse. Scheldebouw, a facade producer in the Netherlands, connected to Permasteelisa, is looking for possible ways to make the construction industry more sustainable. This study aims to reduce the take-make-dispose culture, by creating circular strategies for existing curtain wall facades. It was observed that those facades lose their function before their end-of-life stage is reached. The remaining value and potential that was wasted in this case could be avoided.
The objective of this thesis is to develop strategies to reuse existing aluminium curtain wall facade elements, to diminish waste and reduce resource depletion. To quantify the impact of these strategies the life cycle analysis is used to calculate the amount of emitted carbon. A mixed-method research was conducted, which involved integrating interviews with experts in the facade and material industry along with a review of literature, resulting in the development of a qualitative understanding. Integrating this with reference studies, the application of reuse was further examined. Lastly, strategies have been formed, which have been applied to a relevant case. Facades do have the potential for reuse, as demonstrated in this study. Facades play a crucial role in enclosing indoor spaces, which leads to various specific characteristics that make both facade structures
in themselves and in their reuse rather complex. Facade systems are often uniquely developed, making it difficult to locate a match for reuse. Eight general strategies have been defined to create incentives for reuse. A method for calculating the avoided carbon was created to quantify the potential of the strategies and provide an incentive for clients to include these circular strategies. Overall, the research outcomes offer a framework that has the potential to reduce resource depletion and increase value retention in the facade industry. Crucial elements were determined and components that show potential for reuse were defined. Risks and uncertainties have been identified, as well as the need for
incentives for producers, clients, and policymakers. As mentioned above, finding a receiving project that matches the donor material and designing with these materials still appears to be difficult. Regarding carbon emissions, beneficial strategies were defined. Refurbishment can achieve an 86% carbon reduction with 99% of the materials being reused. Re-manufacturing offers a 49% overall carbon reduction with a 59% material saving. Challenges lie in glazing reuse, particularly sealant and spacer components. Implementing re-manufacturing with glass replacement saves 27% embodied carbon and reduces waste by 21% at the donor building and 28% in the product and construction
stages.

To lessen our influence on the environment, we are moving towards solutions that can meet our needs of shelter, nutrition, mobility, communication, and health with little to no energy or resources. In the construction industry, adaptive façades have gained attention for their capacity to adapt to changing conditions. These façades can modify their state in response to varying factors such as temperature and sunlight. This adaptability offers potential benefits in energy efficiency and occupant comfort, making them significant in architectural advancement. Despite being promising, these technologies are seldom used in buildings because they consist of numerous components and intricate mechanisms that can hinder their overall lifespan. To find more straightforward solutions for these systems, designers and researchers have focused on Smart Materials in combination with passive strategies. Shape Memory Alloys (SMAs), in particular, have found applications in diverse designs owing to their dual functionality as temperature sensors and actuators. SMAs have the remarkable ability to ‘remember’ their original shape and can revert to it when subjected to specific temperatures. This unique trait enables them to serve as both sensors, by detecting temperature changes, and actuators, by initiating shape changes in response to those shifts. However, current SMA-based sunshade designs do not provide visual contact with the exterior, as they continuously block the occupant’s field of view. This work aims at lowering the mechanical complexity of SMA-based sunshades while maintaining thermal comfort and visual contact with the exterior. The first part highlights the significance of precise control strategies for effective sunshade designs. The research emphasizes the importance of tailored control methods aligned with climate conditions. The conclusion underscores that an optimal sunshade design must balance cooling demand reduction, thermal comfort maintenance, and opening hours. Mechanical designs should minimize components while ensuring maximal stroke capabilities. The mechanical design of the counterAKT system exhibited promising stroke results despite not reaching the 200% benchmark. Further research avenues are suggested for textiles and Shape Memory Alloys (SMAs). Integration of findings from both materials is essential for realizing a complete working counterAKT system. Nodal thermal modeling provided insights into the major factors influencing SMA temperature in the counterAKT system. Solar radiation and convective heat transfer were identified as key contributors. The conclusion recommends future research to shift reliance from outdoor air temperature to solar radiation by enhancing emissivity, reducing convection losses, and concentrating solar radiation on the SMA. Finally, The system’s feasibility is demonstrated through a small-scale prototype, affirming its practical viability and potential applicability.

The challenge of global warming is an increasing concern of the 21st century. The concept of sustainability is therefore considered of high importance. A major problem of the Dutch government is the growing housing demand. Also after the WWII, the Netherlands faced a housing crisis, resulting in about 847,000 council houses. The massive number of flats combined with the aforementioned deficiency of houses and the climate problem prohibit large scale demolition and reconstruction, as this would lead to both a further short-term deficit of houses and emission of greenhouse gasses. A timber top-up on council estates constitutes a sustainable approach, which accounts for densification and the huge building stock in city centres. Therefore, this research is aimed to develop a method to optimize timber top-up designs for council estates, considering structural limits and environmental impact.

It is found that the building period impacts the structural variety in council estates. Hence unfortunately no universal structural lay-out can be defined. Based on a norm comparison, two flowcharts are produced to predict the overcapacity of distinct council estates. A modular cross laminated timber (CLT) unit and a non-modular timber frame extension (Dutch: houtskeletbouw) are considered. Material minimalization formed the decisive criterion to determine the most effective variant. Therefore, a 3-step method is developed, which considers the flat characteristics, structural overcapacity and minimalization of material use.

To conclude, it is generally not possible to tell a priori which of the two considered timber top-up methods is the most effective for a particular case. Further, it can be concluded that timber top-ups form a sustainable replacement for combined demolition and reconstruction of buildings. Moreover, these facilitate the realization of a substantial number of houses. Therefore, a vertical extension of council estates forms a sustainable solution to the current housing demand in the Netherlands.

Conventional construction techniques are unsustainable and expensive due to longer construction time, labour-intensive work, and the use of formwork. 3D concrete printing is seen as a potential substitute to overcome these issues. However, extrusion-based 3D printed structures exhibit a weak interlayer bond, and researchers have tried to address this problem through techniques such as using cement mortar layers or vertical steel reinforcement between the layers. This study aims to address the problem of the weak interlayer bond by implementing the phenomenon of 'topological interlocking' to increase the mechanical interlocking between the layers. The study performed scale model printing in the form of mould-casting and caulk-gun extrusion to produce specimens to analyze the effect of grooving on interlayer bond strength. The results were counterintuitive to the previously observed research, and the study recommends avoiding issues that may interfere in further similar studies.

Although relevant information regarding the curtain walls structural damage state is available, hardly any data referring to the seismic loading effect on the overall façade performance is found in the literature. The present research attempts to assess the unitised curtain walls seismic performance by identifying the occurring damage mechanisms based on full-scale testing and finite element modelling.
The study initiates with a state-of-the-art discussing in detail the relevant research areas. Additionally, an introduction to the curtain wall numerical modelling field is provided. This literature review originates both from full-scale experimental testing and findings of academically developed finite element models. The case study of an experimental procedure is also described accompanied by the curtain wall response to the inter-storey drift implementation.
The modelling approach is introduced by presenting the mechanisms and the recreated curtain wall behaviour. Additionally, the process of identifying the properties of the curtain wall the boundary and loading conditions is displayed. The various modelling phases, the initial numerical development, its improvement through the calibration with the experimental results and the calibrated version, are also included.
The accomplishment of the first global curtain wall numerical model using DIANA FEA is a main research objective. The novelty consists in the exploration of the software possibilities and limitations which, although widely used for numerous applications, it hasn’t been utilised for façade numerical modelling. In general, the numerical representation of façade systems aims to provide a better insight of the curtain wall behaviour that will be eventually accurate to the extent that experimental tests won’t be needed for their validation.
Another interesting area is the correlation of the numerical behaviour to the experimental results measured on the curtain wall mock-ups while undergoing seismic loading. The model calibration intends for a realistic representation of the actual performance as recorded during the full-scale testing. Additionally, the contribution of structural silicone sealants in the system post-earthquake behaviour through the comparative performance of façade samples with dry gasket and systems with structural silicone is assessed. This evaluation aims to reinforce the knowledge regarding the strengths and weaknesses of wet and dry configurations and to indicate their appropriate application.
The research attempts to contribute to the seismic risk assessment of unitised curtain walls by identifying the governing failure mechanisms. This evaluation is performed with regards to the silicone sealant, simulating both dry and wet configurations. Thus, a sensitivity analysis varying over the structural silicone bite is developed with respect to the façade ultimate failure. The curtain wall overall response is addressed by evaluating several parameters (displacements, distortion, rotation and maximum stress per component). Moreover, the detection of the largest stress values occurring per element is used for the utilisation factors determination. This occurs by comparing the maximum stresses with the respective design values. The different outcomes provide the constructive context for further research of the façade response under seismic action. The study finalises with conclusions, considerations as well as suggestions for further research. Various challenges encountered are also introduced, aspiring to provide helpful information for future modellers.

Despite being a critical aspect in improving the building stock’s environmental performance and achieving the global environmental goals, the retrofit of traditional historic buildings is hindered by a lack of comprehensive guidelines tailored to their complex building physics and heritage preservation requirements. The conventional retrofit approach – relying on the combined airtightness and insulation improvements – fail to address two decisive aspects of traditional historic buildings:
First, the air leakage is a core contributor to their bioclimatic systems and building physics balance, making its sealing detrimental to their construction durability and their Indoor Environment Quality (IEQ). Second, their heritage protection requirements restrict the conventional retrofit interventions, and particularly hinder the implementation of the mechanical systems needed to mitigate their associated risks on the building and its occupants. Accordingly, there arose an interest in challenging the conventional depiction of the air leakage as an overhead to be eliminated, and in developing a retrofit approach that preserves breathable buildings’ inherent operations by exploiting their air leakage into achieving their optimal post-retrofit performance, accounting for both energy-efficiency and IEQ.
A potential solution to the feasibility of such strategy considered a natural phenomenon characteristic of the diffuse leakage through breathable envelopes – the infiltration heat recovery (IHR) – that is conventionally neglected in building performance assessments. The intentional and efficient exploitation of this effect results in construction elements, referred to as Dynamic Insulations (DI), in which air leakage could act as a heat exchanger, diffuse ventilation source, airborne contaminant filter, and diffusion barrier. Although their original design and operations were not tailored to efficiently harvest the IHR effect, the existing breathable constructions reveal similarities with DI systems. This suggests the potential of retrofitting them to act as an efficient DI system, thus exploiting the air leakage into the building performance improvements. The present research aimed at identifying the envelope and ventilation retrofit variants that would optimize the IHR utilization through the construction, as to provide for performance improvements comparable to (or better than) the conventional approach while preserving the breathability of the construction and minimizing the heritage disruptions.
The study proposes a comprehensive framework for the assessment of the building’s post-retrofit performance, in terms of its energy-efficiency and IEQ, and investigates the relevant retrofit variants to make performance-based decisions in the retrofit design for traditional breathable buildings. This performance was evaluated using a comprehensive building performance simulation (BPS) model.
For a reliable representation of the complex building physics and air leakage dynamics of breathable constructions, the BPS integrates three sub-models: the building energy simulation (BES) model, the air leakage model, and the dynamic insulation (DI) model. Due to a lack of BES tools simulating dynamic construction properties, the well-established analytical Taylor model was adopted and adapted to the dynamic simulation tool. The analysis was implemented in EnergyPlus, for its integral Airflow Network (AFN) and advanced Energy Management System (EMS) capabilities. The model’s validation process revealed significant limitations and highlighted a need for BPS tools capable of more efficiently incorporating the dynamic behavior of building materials and their interaction with dynamic flows, particularly when seeking the tailored, efficient and non-intrusive retrofit of historic traditional buildings...