The construction industry accounts for a significant part (39%) of the global greenhouse gas (GHG) emissions, additionally it is accountable for 40% of all extracted materials, 40% of primary energy usage and 40% of the total waste generated. Adding up to CO2-emissions in the form of embodied or operational carbon. Meanwhile the temperature limit set in 2015 signed Paris Agreement with the purpose of reducing the global temperature increase, is being exceeded

If the global GHG-emissions are not reduced the global temperature rise will increase even more, and with that the severity of the climate change consequences. GHG emissions in the building sector can be decreased by reducing operational and/or embodied carbon. Since embodied carbon is getting increasingly higher but lacks in research and innovative solutions, this research explores the possibility of reducing embodied carbon by designing a reversible discrete timber system as alternative to a conventional structural timber element or system.

For this a joint that is reversible and applicable to discrete timber elements must be found and tested. Five joints from a larger list were selected based on simplicity. In order to determine the loads on the discrete timber system, a case study was set to be a post war apartment block in Rotterdam South. The selected joints were analysed to determine what would happen if a load is applied to this element. The load showed highly localized peak stresses in the joints, indicating that the joints might be the weakness of the discrete timber elements, the rest of the element showed expected behaviour. In the end a simple square cog joint is the most suitable.

Besides testing the discrete timber elements, the discrete timber systems also needed to be tested to see how they would react under the applied loads, and what the resulting maximum displacement and utilization values would be. Here various ways of aggregating discrete timber elements was tested. These aggregations were influenced by parameter such as the scaling factor (where a normal straight column, was scaled variedly into a mushroom-like column), dimensions of the base of the discrete system, the dimensions of the cross sections and the material of the discrete elements. The results from these tests showed the effects from the various parameters on the maximum displacement and utilization of the discrete timber system.

However, there are also some gaps with regards to which joints are suitable, moreover, can the joints be made in timber or should there be resorted to a reinforced joint in a different material than timber? One of the main strengths of a discrete timber system lays in its reversibility, and for the system to be reversible there must be a demountable joint.

Discrete timber systems can be a feasible alternative to conventional structural timber by ensuring that the discrete systems have strong, reversible joints that are simple in production and construction.

Due to carbon emissions and increased global temperatures, the need for carbon neutral materials is rising. As of 2024, the use of timber is growing rapidly. Still, timber is not the preferred material in the construction sector. As modern architecture is getting more complex geometries, 'fluid' construction materials like steel and concrete dominate the building sites. As timber has a straight geometry, making curved and complex shapes is not desirable. However, timber is a porous and hygroscopic material, it can absorb water from its surroundings and become more flexible. This characteristic has been utilized for over many centuries. By processing glulam or lvl beams or columns with steam or adhesives and clamps, curved structural elements can be manufactured. However, these bending methods are energy- and work-intensive and result in products which are not sustainable in terms of re-usability, recyclebility, etc. Furthermore, curved structural elements can be more efficient in terms of load distribution and material usage than the rectangular and straight counterpart. This thesis aims to research and develop complex structural curved floor elements produced with passive self-shaping.
After an initial bi-layer self-shaping test, multiple different typologies were designed, tested and compared with a conventional capped ceiling. Interconnections, treatment processes, assembly orders and timber species were investigated. For an efficient capped ceiling floor element, the curvature height to width ratio should be between 1/8 and 1/12. The elements designed and tested with both a water and a moisture treatment showed a maximum ratio of 1/45 or 26.8% of the 1/12 ratio. Meaning that it is possible to manufacture and produce a complex self-shaping floor element. There is much potential for the structural floor elements to reach the 1/12 ratio, however this could not be achieved during this research thesis.

The project explores ways to enhance sustainable building practices by addressing the impact of material availability on the construction industry. Instead of assuming materials are infinitely available, this study examines the implications of treating them as finite resources. Timber was chosen due to the complexities in reusing it and the lack of established workflows for its reuse.

A thorough literature review identified key aspects for developing effective timber reuse practices. Based on this, workflows were created to translate critical research aspects—such as structure, grading, matching, and product—into practical applications. These workflows aim to assist carpenters and wood structural designers in creating structural elements, especially interlocking solid timber joists. These joists are designed for easy assembly and improved structural performance of wooden beams without complex techniques.

The workflows were rigorously investigated and refined for feasibility. Experiments assessed material behavior, focusing on topological potential, challenges, and limitations. This research aims to develop robust workflows that support sustainable timber reuse in construction.

Almost 40% of annual gas emmissions globally are produced by the construction sector. Due to the housing crisis of the Netherlands, the ministry of Housing and Spatial Planning wants to build almost a million dwellings before 2030, double the number of dwellings normally built in the same period. With that come greater gas emmisions. This growing amount of emissions however, can decrease drastically by using local and natural materials instead of the often used steel or concrete.

This research therefore aims to explore the potentials of natural local fibers for structural materials within new architecture. The use of these materials could reduce the carbon emissions greatly, while also bringing back the local identity of a place, that is now mostly lost due to a lot of generic, one-size-fits-all architecture.

This research begins with the investigation of local, natural materials that already have been introduced as building materials in the Netherlands historically and evaluates other natural fibers and their availability. The research soon delves into willow fibers and their properties and potentials. The final results provide an insight into the structural properties of different species of willow, a design for a structural element, its potential implementations within architectural projects and the possibilities of using this fiber on a big scale.

A configurator is a platform which serves the goal of mass customization. It contains a set of common components from which a stream of derivative products can be efficiently developed and launched. Configurators in the construction industry have the potential to help integrate the design-to-production supply chain. Integration is required because there is a rising complexity in design and construction projects due to an increased number of parties involved in each venture. Configurators achieve integration by ensuring that a design is within the production capacity. (Cao et al., 2021) identified three distinct typologies of existing construction configurators: planning, design, and production configurators. These typologies primarily indicate the stage of the construction phase in which the configurator is used. An integrated configurator includes all typologies/phases. The application of configurators in construction is limited and immature, this is especially the case for integrated construction configurators. The application of configurators in construction is limited because current configurators lack scalability, many configurators may only be fit for one generation of products from one company. This issue originates from insufficient cross-organizational collaboration and integration with supply chains. Additionally, academia indicates a need for research on increasing the design space of modular buildings. For this reason, the research question of this thesis is: How can the design space of integrated construction configurators be enlarged? The approach for developing an integrated construction configurator which increases the design space is inspired by games with building systems such as Valheim. It consists of a grid, modularity on building component level, and configuration rules which dictate how components are placed on the grid. However, a major limitation of these games is the lack of proper analytical tools to validate configurations for physical construction. A configurator was developed which overcomes this limitation by implementation of a structural analysis. The configuration process of this configurator consists of 3 parts: the grid, the components, and the analysis. The grid defines the design space in which components can be placed, components from a building product database ensure product manufacturability, and analyses ensure that the assembly of components is possible. In each iteration of the configuration process, the configuration is controlled by editing the grid and placing or removing components on the grid. Then, the configuration is evaluated by means of analysis, results from the analysis are the basis for edits to the configuration in the next iteration cycle. The main benefits of this type of configurator compared to BIM are that by integrating the manufacturing and assembly constraints in the design process, early design decisions are evaluated on manufacturability. This can avoid design issues that require reorganisation efforts and put pressure on the supply chain. Consequently, the configurator reduces the time and cost for the design and production phases, allowing users of the configurator to develop buildings faster and cheaper.

The current sustainability crisis requires a shift in the way material availability is currently considered. The current trend is to dispose of material easily after it has served its first purpose, while often the material still has potential to be reused. The construction sector is a large contributor of the extraction of virgin resources, leading in the case of timber to deforestation. In The Netherlands alone around 1.740 kiloton waste wood is collected annually. 23% of this wood consists of solid non-glued or treated reusable timber, translating roughly to a waste stream of 450kton of reusable wood that is discarded. The current design approach requires shift, instead of design for manufacturing designers should focus on designing with what has already been manufactured. The design concept of discrete timber is well suited for this design approach as it involves building a structure or element out of smaller parts. This method allows for direct reuse and repurposing of a varying stock of discharged timber pieces, effectively enhancing the life-cycle of timber from a currently down-cycling scenario into a circular loop. Moreover a discrete system is not beholden to the traditional implication of uniform an rectangular cross-sections and a geometry can be easily optimised to the acting forces by leaving out parts on lower stressed area’s. Using programming and optimisation techniques, this thesis focusses on creating an efficient and adaptable structural system from a varying stock of reclaimed timber pieces while maximizing the future reuse potential of the used parts. The main computational problems addressed in this research are efficiently filling a design domain with available stock and minimizing cutting losses, and structurally optimising the design domain. An algorithm is created in the visual programming environment Grasshopper in combination with Python. The algorithm discretizes a given design space into the pieces found in the database by sequentially solving three combinatorial problems. The algorithm optimises the placement of the pieces so that higher strength grade pieces are placed in area with higher stress levels. The assembly is optimised by removing all non-vital structural parts resulting in a final efficient structure. The algorithm's performance is tested on stability of results, optimisation method, size influence of parts, filling rate of the design space, strength grade influence and buckling. This work serves as a prove of concept for designing with a highly versatile stock of reclaimed components.

Traditional methods of building with concrete are materially wasteful, highly polluting, and often structurally inefficient. The vast global consumption of concrete plays a large role in the construction industry’s negative effects on the environment, necessitating a significant change in the way we design and build with concrete. The fluid properties of concrete combined with the flexibility of knit textile formwork makes it possible to shape concrete into complex, innovative structures that drastically reduce material consumption and waste.
KnitCrete, which employs CNC-knitted textiles as flexible formwork for casting with concrete, has demonstrated the extraordinary potential of this technology to efficiently fabricate complex geometries without the need for costly, time-consuming rigid molds.
The objective of this research is to develop a pattern-specific knowledge base to support the future design of innovative architectural forms and structures using CNC-knit textile formwork. Through three main parts, the research approach investigates the implications of pattern selection on the behavior of the resulting concrete forms. The study employs a combination of information-based and inspiration-based design research methodologies. In the first phase, a comprehensive pattern repository is developed which catalogues relevant information for 21 different knit patterns. In the second phase, rigorous testing of each pattern under hydrostatic loading is performed and a deformation analysis is performed. The third phase involves an exploration of pattern combinations, supported by the information gathered in phases one and two, which demonstrates the potential of this technology to create complex or double curved geometries.
Key findings reveal that pattern selection significantly influences the structural and aesthetic properties of the resulting concrete forms. The comparison between warp and weft properties highlights distinct behaviors under hydrostatic loading with significant implications for flexible formwork design. Challenges in the precise calibration of combined patterns and controlling deformation during casting underscore the complexity of implementing CNC-knit formwork. Contributions to this field include advancements in understanding knit textile behavior, a replicable research approach, and interdisciplinary connections between textile engineering, material studies, and architectural design. In summary, this research lays a robust groundwork for future research and design in the field of CNC-knit textile formwork with a specific focus on knit pattern behavior.

The construction industry is responsible for the emitting carbon, nitrogen, and particulate matter, which is harmful to the environment and contributes to global warming. Municipalities in the Netherlands plan to reduce emissions in inner-city developments to zero before 2030, for which a transformation of the already complicated construction supply chain would be necessary. The unique characteristics of the construction supply chain; temporary coalition of organizations working on one-of-a-kind projects, complicate reduction of supply chain emissions. In other sectors like manufacturing focal firms take in a central position between the demand and supply system and can align the supply chain. In construction the developer translates demands from society, the public and customers into projects that are executed by core supply chain stakeholders. The main question to be answered in this thesis is: How can real estate developers organize a low-emission supply chain for high-rise construction in Dutch cities? A literature review on green construction supply chain management and construction emissions have given insight into the drivers, barriers, and roles of different stakeholders in low-emission design, -procurement, -logistics and -construction & manufacturing. Inner-city high-rise case studies and semistructured interviews with relevant stakeholders within these projects were conducted to draw lessons from practice. Developers can have a big influence on construction emissions through setting ambitions and translating these low-emission ambitions in the criteria for the procurement of services and materials for all supply chain stakeholders. In design, close collaboration with the architect and early involvement of the contractor and relevant expertise can help implement low-emission practices. Logistics and construction & manufacturing emissions can be influenced through contractual agreements with contractors, subcontractors, and suppliers, but should not be a direct responsibility of the developer and ask for active involvement of the government.

In a time of increasing awareness for the environment and rising energy prices, an efficiency in our material use is of paramount importance. This research is built on the notion that the design of light structures has a positive effect on the energy use of the built environment. The tent has been chosen to examine this approach of lightness in the domain of architecture. In an attempt to make the tent more efficient, the parasitic properties of the tent system are utilized by attaching it to an infrastructural object that can be found everywhere in the world: The Flyover. In the paper, a framework is developed to classify boundary tensioned membrane tents (a branch of the tensile structure systems), combine twelve of those types with the flyover, and evaluate the combinations by measuring them against spatial and structural attributes. The design portion is focussed on a a metro flyover in Rootterdam South. Multiple small-scale intervention will be introduced to heal the urban fabric surrounding this flyover.

The rapid growth in building stock and the demand for new construction present significant challenges in terms of material scarcity, waste production, and greenhouse gas emissions. To address these challenges, a fundamental shift in the construction industry's approach is needed, viewing waste as a resource through circularity principles. This research focuses on the application of circular principles and resource efficiency in the reuse of structural steel within the European construction industry. However, the utilization of reclaimed steel in construction projects faces significant challenges, including the condition of reclaimed elements, the need for repairs and refurbishment, unclear stakeholder responsibilities, and the absence of contractual frameworks. Communication gaps and coordination complexities further compound these challenges.

Despite these obstacles, the research demonstrates that reclaimed steel can be successfully integrated into projects with proper planning, coordination, and expertise. A comprehensive analysis of existing practices and challenges, interviews with industry professionals, and literature review inform the development of a design framework and a computational tool.

The proposed design workflow incorporates strategies to address the identified challenges and promote efficient steel reuse within the different project phases. Additionally, a computational tool facilitates the integration of reclaimed steel through a digital inventory and matching algorithm. The matching algorithm enables the retrieval of stock information from a digital inventory. A matching algorithm is implemented to compare the list of design elements needed for a project with the available stock list. This tool efficiently identifies possible substitutions, enabling designers and engineers to find suitable reclaimed steel sections for their projects. Lastly, the design workflow and computational tool were successfully tested through a design case study, demonstrating their effectiveness and environmental impact results to allow users to make informed design decisions.

Overall, this thesis project offers valuable insights and practical solutions to advance the implementation of steel reuse in the construction industry, making a significant contribution to the field of sustainable construction.

The construction industry and the existing building stock are significant contributors to greenhouse gas emissions. To address this environmental challenge, there is a growing interest in using bio-based materials, such as wood, in architecture. Yet, the availability of wood resources is limited.
Bamboo, a non-wood species, holds promise as a potential substitute due to its rapid growth rate. However, its adoption in the construction industry remains limited due to the challenges posed by its hollow tube anatomy and the lack of established building codes for its use.
To overcome these challenges, this study proposes the utilization of bamboo in a powdered and fiber form to create a more versatile and standardized building material.
Additive manufacturing techniques, which have seen significant advancements in the past three decades, have also made their way into the construction sector, traditionally slower in adopting innovations. These additive manufacturing technologies offer the potential to reduce labor costs, minimize material waste, and enable the fabrication of complex geometries that are challenging to achieve using conventional construction methods.
While 3D printing technologies for concrete and steel structures have made significant progress, the research and application of additive manufacturing with bamboo for construction purposes still lag behind.
The thesis aims to address this research gap by developing a building component made with bamboo using additive manufacturing technology. By leveraging the benefits of additive manufacturing and utilizing bamboo as a renewable and versatile material, this thesis seeks to promote sustainable practices in the field of architecture.

The construction industry’s impact on carbon emissions, pollution, and resource depletion necessitates innovative approaches to reduce environmental harm. This research explores the use of computational design, digital fabrication, and timber as a renewable material to mitigate the construction industry’s environmental impact. Timber is recognized as a low-carbon solution for affordable housing, offering a means to decrease emissions in building construction.
This study presents an innovative automated construction workflow that involves human-robot collaboration (HRC) for a discretized timber construction system. To demonstrate the capabilities of the system, a housing design is developed for a specific location in Rotterdam. The research considers the site context as a guideline to establish boundary conditions for implementing the developed construction system. It addresses the issue of affordable housing, transcending the chosen site context, as it is a global concern. The design incorporates circularity principles, including modularity, design-for-disassembly, design-for-reuse, reconfigurability, and extension of material lifespan. A combinatorial design workflow is proposed, focusing on the assembly of generic discrete elements into function-based aggregated structures that can be rearranged over time.
In order to prove the concept, an HRC assembly prototype is established to mount the discretized aggregation structure, utilizing demountable connections to join the elements while asking the human participation. This approach enables the reassembly of the structure multiple times, promoting material reuse and extending the structure’s potential.
The research contributes to the advancement of the circular agenda in the building industry by implementing essential digital design and manufacturing concepts into an automated construction process. By extending the material life cycle and carbon store, the proposed workflow demonstrates the potential for sustainable and efficient construction practices in the timber housing sector.

The life span of buildings is currently largely determined by economic motives. This often results in a large number of vacant buildings, or unsubstantiated demolition. Since the building industry has the most significant consumption of natural resources compared to other industries worldwide, it is important that the ecological motive gets prioritized more. A strategy to minimize the use of new materials and prevent demolition is to adapt existing buildings to new functional requirements. Current existing buildings are most often not built with the intention to be adapted in the future, making adaptation activities not feasible. Structures that are intented for future adaptation, are mostly focused on complete deconstruction, while most functional changes only require small adaptations. The aim of this research is to develop a framework for the design of adaptable load-bearing structures, focused on adapting individual building components to extend the functional life span of a building. Since there is a level of uncertainty related to the future life span of a building, a scenario based design method is used to formulate different design scenarios to which an adaptable structure should comply. The framework consists of five design domains: material, structural layout, kit-of-parts, building layers and construction process. These domains are explored parallelly on the aspect of adaptation and are evaluated using circular design qualities. The design proposal addresses a structural principle that consists of a primary and secondary connection, in which the secondary connection is used during an adaptation process. The adaptable structural system performs better on the circular design qualities when compared to existing circular systems, mainly on the independency and compatibility. However, the adaptability performance of a building is not solely reliant on the load-bearing structure. This principle only works when the other building layers are also designed with adaptability in mind. This research contributes to the building industry research field by providing a well-rounded overview of factors where adaptability could be implemented into the design process and rethinking the approach to handling the life span of a building.

At the moment there is an increasing shortage of raw materials. The approach of a circular economy can be used to reduce the need for new materials. This includes design for adaptability. During interviews and a literature review, methods that are used to increase adaptability were determined, including oversizing elements and demountable connections. Oversizing elements leads to an initial increase of material use but removes the need to make changes to the structure during the building’s lifespan. On the other hand, demountable connections don’t increase the material use, but do lead to a need for changes being made to the structure. Therefore, there is always a balance between material use and adaptability. The main research question of this project is thus: “How can a computational workflow be used to increase the amount of adaptability in the design of a building’s structure, while minimizing material use?”.
The method of scenario-based design can also be used to increase adaptability, by anticipating how the building could change to meet the user’s needs over time. Scenario-based design can be combined with a computation workflow, which makes it possible to easily test many scenarios. The main reason why there are still limited adaptable buildings being constructed is the higher costs of these buildings. For instance, due to the higher material use of over-sizing elements. To lower the costs, it is possible to only apply adaptability measures where they are needed. 
During this project a computational workflow is created to determine where the measures are required, by applying scenarios to a preliminary design. The workflow can also be used to compare multiple grid-sizes, as this is an important aspect relating to both adaptability and material use. The workflow uses an optimization process to determine the minimal number of changes that are required for the structure to adapt to the different scenarios. Another optimization approach was also used to determine the minimal mass of the structure, after the structure has been adapted. However, this second approach was unsuccessful. 
The optimization process results in the minimal number of elements that need to be demountable or over-sized. The workflow creates a list of which elements need to be replaced with a larger cross-section for each of the scenarios. By combining these lists, all elements that might have to be replaced can be determined per design variant. By comparing mass and lowest number of demountable elements, the most suitable design variant is determined.
A test-case is used to determine whether this approach is beneficial for material use of the structure. From this test-case it was found that the structures optimized by the workflow can result in less material being used over the building’s life span if the scenarios are correctly anticipated. In case the scenarios from the workflow don’t match with the scenarios that will actually take place, the structures from the workflow offer no benefit over the traditional structure. The functionality of the workflow therefore depends on the scenarios that are determined during the design process.

In recent years, the Netherlands has witnessed a growing housing shortage, prompting an ambitious plan by the government to address the demand through increased construction of new housing until 2050. Moreover, as part of environmental commitments, new dwellings and existing housing stock must align with current energy performance standards and the circular goals by the same target year. Hence, exploring alternative ways of increasing housing capacity
is crucial to meet the growing demand while ensuring alignment with the environmental requirements.
This research examines timber top-up’s structural feasibility and circular potential to expand existing dwellings’ area as an alternative to a common practice: deconstruct followed by building new. Furthermore, provide an approach to the circular principle of Reuse to transition existing Reinforce Concrete structure in dwellings from a linear to a circular economy. The present thesis consists of a literature review analysis of the potential of mass timber to top up, followed by the analysis of two local case studies that implemented this strategy. Then a dwelling with a relevant RC structure typology in the city of Deflt is selected as a case study to propose a conceptual modular structural design for a Timber Top-up system.
Three scenarios with different area capacities are proposed and tested to analyze the structural feasibility based on four structurally defined criteria (Reaction in the foundations, Utilization and reactions of the main RC structural components & timber components & deflection limit), followed by the analysis of the CO2 footprint of the Top-up scenarios. The tests are performed with the parametric structural analysis plugin Karamaba 3d, followed by the use of the software Granta Edupack with its feature Ecoaduti tool. The result showed that
topping up using mass timber is an effective strategy to reduce the Upfront embodied carbon of existing RC structures while increasing the area capacity of the building.

As a threatening reality to the planet’s stability, climate change has forced the building industry to develop sustainable techniques and materials to fulfil the constant demand for infrastructure. Timber, as a biobased material, appears like a promising option for constructing highrise structures, a typology that, before the creation of engineered wood products (EWP), was impossible due to technical limitations. Today, buildings with timber as macrostructure are being built worldwide, redrawing the skylines of many cities and revolutionizing the way the building is due to its low CO2 embodied carbon and reducing construction time. However, these new buildings still need to improve regarding circularity principles. Today, the timber industry is experiencing a flourishing, even tho timber highrises implement inefficient design constraints that limit adaptability and durability and decrease their advantage of having a lower embodied energy than traditional construction materials. This investigation delves into the feasibility of timber highrise structures and examines various factors that must be considered when evaluating them. The study utilizes a parametric model to determine the crucial role of the core and the influence of structural components in the global stiffness of highrise structures and in potential strategies to maximize mechanical behaviour following circular principles; with the results of structural analysis, a draft study case is proposed in the area of the spatial framework of M4H of Rotterdam. The project proposes a timber Highrise designed with design principles for disassembly, adaptability, modularity, and durability. The building is designed to address the challenge of construction waste generated by infrastructure obsolescence, set a standard for highrise design that is environmentally responsible, and create a symbiotic relationship between the building and its environment.