Nowadays, air ducts components for ventilation used in offices, hospitals and schools are made from non-renewable materials mainly sheet metal and plastics. Continuing to feed the high demand of metals is a challenge and could result of depletion of natural resources. This raises the importance to look into renewable resources with a lower environmental impact and contribute to the transition towards a circular economy. By rethinking the material usage for the duct components, solutions should be found in bio-based materials such as agricultural waste, cardboard, bio-composites or bio-plastics.

This research aims to explore the potential and limitations of bio-based materials for the applicability of air duct components. Therefore the following research question is formulated: What are the potential and limitations of bio-based materials to replace sheet metal for the construction of air ducts by maintaining the same quality?

Relevant literature reviews are conducted to give an understand of the construction and relevant requirements of sheet metal ducts. As well the circularity approaches and the categorization of bio-based materials and related manufacturing methods. A method is developed to classify the bio-based materials according their manufacturing efficiency per type of duct component: linear component, joint, bend and t-component. In addition, an assessment is described based on key criteria to select a suitable material per duct component in which the carbon footprint assessment and comparison is crucial.

In conclusion, the potential for linear bio-based components made from Tetra Pak is more advanced than complex components including joints, bends and t-components. This relates to the production efficiency and the LCA of the analyzed materials. Bio-plastics and composites as potential materials for complex components resulted in a relative high carbon footprint which made recycled plastic as non-renewable material a more realistic alternative.
The limitations lie by achieving a similar quality as sheet metal in terms of moisture resistance and chemical emission. Due to the porous character of most bio-based materials they are sensitive for humidity, increasing the risk of mold growth overtime making the use of bio-based materials and the design of the connections between components challenging. Furthermore, the lifespan of the bio-based materials is unknown which is crucial for an accurate LCA in terms of carbon footprint. Low lifespan indicates more replacements leading to potentially a higher carbon footprint overtime compared to sheet metal.

The building industry is material intensive and is responsible for approximately 40% of the total waste generated across the European Union. It operates on a ‘take-make-dispose’ model due to which key issues such as resource scarcity, waste generation, and environmental pressure occur. The circular economy has been attributed to the need to utilize waste flows more effectively, thereby reducing raw material demand. By 2050, the Dutch Government aims to transition to Circular Economy and organize the building industry in a way to ensure sustainable construction by use, reuse, maintenance and dismantling of objects.

Remanufacturing is a strategy of the circular economy that supports this approach. It is a process of returning a used product to its original performance with a warranty that is equivalent to or better than that of newly manufactured product. It is an important component of resource efficient manufacturing as it reduces the dependency on virgin materials.Through research, it was observed that the principles of circular economy are well established theoretically but lack guidelines that make them applicable in practice. Therefore, the thesis focuses to find out “how” remanufacturing of building products be implemented as a strategy to accelerate the progress towards a circular built environment.
The project develops a remanufacturing canvas and list of criteria through literature study of successful examples of remanufacturing such as Xerox, Caterpillar, Canon, Philips MRI Systems and Davies Office furniture. Further the proposed canvas is validated through a case study of the building De Satelliet of DNB complex to investigate their remanufacturing potential of EoL façade elements which were disassembled with an intention of giving a second life.

The study includes crafting guidelines for the remanufacturing of EoL façade elements. Remanufacturing as a strategy was evaluated through assessments based on Cost, Embodied energy, and thermal performance of the façade elements. The results from the assessments were in favour of remanufacturing. However, it was concluded that while remanufacturing depicts the power of smaller loop and follows all the principles of circular economy, it is important to note that remanufacturing process shifts a large amount of responsibility from a customer to the manufacturer. There is always a risk of creating more impact than virgin production and hence decisions must be supported through results from calculations of embodied carbon and LCA.

Nowadays, the high rate of urban population growth due to immigration and scarcity of land has significantly increased the need for new high-rise dwellings. Meanwhile, the recent building regulations require buildings to be highly energy-efficient to reduce the building’s impact on the environment. However, the inherent characteristics of these new energy-efficient high-rise dwellings put them at higher risk of overheating. In addition, with the effect of climate change, the risk becomes even higher in the future. Though this problem could be addressed by the means of active cooling, doing so will increase the energy consumption of the building, confronting the core concept of the energy-efficient dwellings.
Therefore, this thesis investigated passive and energy-efficient solutions for the overheating problem in energy-efficient high-rise dwellings of temperate climate. Design Guidelines helping designers in addressing the overheating problem in tall buildings were introduced. Then, by applying bundles of these solutions through redesigning the façade of a case study building effectivity of the purposed solutions were investigated for the Dutch context.
The simulation results verified that overheating can still be prevented in the future by passive means. A proper combination of the thermal mass, heat dissipation and heat protection techniques with considering adaptivity in thermal comfort displayed that overheating can be prevented even by the end of the century.

If the Netherlands wants to achieve its goal of being completely circular by 2050 (Berkel, Delahaye, & Faasdreef, 2019), radical solutions must take place. Implementing a circular economy is a challenge, but it proves to be significant given the rate at which resources are being consumed. Designing is one of the most important tasks to achieve the circular agenda. Highlighted by Augusto, Ribeiro and Hotza “considering that design process determines 80% of the environmental impact generate by a product or service, it is important to develop production processes able to support companies in the development of environmentally friendly products or services in a fast, reliable and pragmatic manner” (Augusto, Ribeiro, & Hotza, 2019). The design process has a significant weight in the repercussions a project might have in the environment. Even though such design only refers to the architectonic or product design, the current research takes it a step further and also envisions strategic design. Reverse logistics is a vital component of the circular economy, as it would solve major loopholes and answer the questions that are currently being asked. Understanding the market and having a clearer picture of the behaviour of the materials is vital to assess the current situation and the solutions to be proposed. As mentioned by the Ellen MacArthur Foundation, “thinking of systems” (Ellen MacArtur, 2017) is one of the pillars of circularity, which is what reverse logistics might address. The current research analyses the existing conditions, applied to a specific product, and then proposes a product and strategy redesign to facilitate a reverse logistics process. The general objective is to develop a framework that is useful to analyse current construction practices and that also helps identifying possible solutions, both at product and system level, facilitating the implementation of reverse logistics in the façade industry. At the end, a framework that organizes RL is proposed as well as a theoretical basis for DfRL, Design for Reverse Logistics, considering the steps needed to facilitate RL. An application of both formats is performed in a specific case, the CITG building facade panel, and an eventual design exercise is made. Universal panel solutions are proposed, a configuration that will allow interchangeability between products.

The overall aim of this research is to review existing facades produced by a leading façade manufacturer and develop new systems corresponding with the company’s main product features and improved for Circular Economic performance by applying the principles of Design for Disassembly. The study is based on a literature research about the Circular Economy, Design for Disassembly and relevant assessment systems for the two terms. Existing projects are reviewed and the findings translated into guidelines for future façade developments. With the guidelines in mind two new systems are developed and rated for their performance on Circularity and Disassembly. The first part of the paper examines the current status of the existing facades for Circularity and Disassembly potential. The second part provides evidence that the adoption of the guidelines can lead to better performances, either incremental by applying limited changes as per produced guideline or more substantial by redesign. For practitioners working on innovative façade systems in the realm of the circular economy this paper provides basic guidelines for designing and rating their concepts. This paper reviews a specialist product on its potential for Circularity and Disassembly, aspects currently gaining in importance.

Context - In the construction industry of today, buildings are seen as finished products rather than ongoing processes. The business model of facades as a product service system is a promising strategy to change these practices. A pilot project at Delft University of Technology sparks the interest of Alkondor Hengelo, to explore their tasks and responsibilities as pioneers in this new way of supplying facades. Suppliers would retain the ownership of a leased PSS façade and guide a project through its entire service life and beyond, managing materials in a circular way. The two main challenges were identified as 1. Going from a linear model to circularity, and 2. The ongoing involvement in a PSS instead of handing over their product. The first steps of implementing the façade leasing model have been taken, however the full strategy yet needs to be outlined, to understand how value is added for suppliers and clients and where technical barriers are found.

Objective - Ideally, a PSS would optimize façade performance and provide all services that are needed to do so. This adds value for the client and creates a steady source of income for the supplier. As the pathway to a full PSS is best approached in smaller steps, it should be defined: What set of tasks would the façade supplier take on in a basic stage of servitization, and what could be added on to form a more advanced service agreement? For façade suppliers, it is important to make the best use of the investment into their product, as they would not only be acting as producers, but also operate and safeguard the product and its performance throughout the entire cradle-to-cradle life cycle. Therefore, it should be designed for optimal operation and output during use, and designed for circularity, to achieve a high residual value after the first use. Different design criteria and considerations are therefore given, as a reference for future designers of circular facades as PSS.

In Europe, 1/3rd of all the products reaching recycling facilities can be sold as secondary materials, and this can be a high-quality replacement for low-quality new products. Circular Material Use rate shows how much material demand was catered by reused or recycled content. The Netherlands was estimated at 29% in 2016 is the highest among all other member states and more than twice of Europe’s average. The Netherlands has now set up the goal to become 100% circular by 2050. Principles of circularity aim at lowering the environmental impacts and halve the emissions by 2030 and carbon neutral by 2050, according to the Paris Agreement. However, even though high circularity rates in the Netherlands, 12.2 tonnes per capita of greenhouse gases were released in 2016, which is 3.5 tonnes higher than the EU average. In transitioning to a circular built environment, the most crucial challenge is to keep all materials in a closed loop in a way that proves lower environmental impact compared to extracting a virgin equivalent. In current practice, building materials are procured at the end of a design phase, which results in minimum use of secondary stock and maximum extraction of virgin material to fit “circular” designs. Since buildings are designed for longer lifespans, this virgin material returns as secondary much later and do not reflect in the indicator defined by the EU. The main question is what information is needed by a designer or engineer in procuring secondary materials and when & how it can be best provided to them. This research gives an Assessment Framework to assess parameters such as the circular flow of materials,embodied CO2, cost and technical performance while designing.It is composed of five significant interfaces - material database, material explorer, assessment dashboard, digital design and a visual script toassess various parameters such as MCI, embodied CO2, distance from the project site, cost, U-value, Thermal conductivity, Density and other labels in 3D.The framework provides a Preliminary and Advanced assessment of different parameters. The only difference is that Advanced assessment takes into account is the disassembly potential of various components at a system level and determines whether they can be reused or have to be demolished at EOL. Demolition would mean a product reach EOL sooner, which result in higher embodied CO2. Hence, allowing design/engineering optimization. Other instance, where a component reaches EOL before its surrounding product, replacement of that component should not result in the demolition of others.

Context
The “take-make-dispose” linear model has proven to be highly unsustainable during the past decades. A circular economy has emerged as a model that is restorative by design, and a response towards the high material and energy intensive linear model. However, a transition to a circular built environment implies a radical change in design and construction. Remanufacturing is one of the three product life extension strategies located in the technical cycles from the circular economy. It is an alternative to demolition, and it allows products to be longer in use, with a constant upgrade. However, for products to be remanufactured, they have to be designed according to certain guidelines, and supported by the application of circular business models.
Kawneer, an American manufacturer of aluminium architectural systems and products, seeks to optimize façade systems to meet the demand for circular building products. This means that the components of the systems should be designed with product properties such as disassembly, modularity, and flexibility, which allows them to be circular. Different (re)life options, such as reuse, remanufacturing, and refurbishment, should also be taken into account from the early design stages. The RT82HI+ window system is one of the most competent products manufactured by Kawneer. However, the only (re)life option currently available is recycling. Therefore, the product is currently unable to meet the requirements of a circular building product.
Objective
The objective of the presented research is to evaluate the performance of the existing façade components of the RT82HI+ window system in a circular economy, and according to such, redesign towards remanufacturing and other product-life extension strategies.
This is done, first, through the understanding of the relationship and dependency among the product design, development, and product-life extension, especially remanufacturing. Secondly, through an analysis of the current lifecycle scenarios of the existing components, and identification of their challenges and potentials in a circular economy. And third, through the elaboration of three different circular window systems that react upon the main findings from the analysis.
Main Findings
Three different designs are explored. The first one is an optimization of the existing RT 82 HI +, where only the critical aspects are redesigned. The second and third are hybrid variants that combine aluminum with wood polymer composite pro les (WPC). These three designs are assessed under the principles of DfD (Design for Disassembly), DfA (Design for Adaptability), and DfRem (Design for Re- manufacturing). Additionally, different remanufacturing, reuse, and adaptability scenarios are analyses to understand the performance of the window system in a circular economy.
On the other hand, four main different types of façade systems and construction are reviewed to understand the type of attachment of the window to the construction. This resulted in a critical point because it could affect the performance of the window in terms of circularity.
The results indicated improvements in different aspects. The key one was ease of assembly and disassembly, but also in terms of type of connections, and geometry of product edges. Furthermore, it is discussed how the loop is closed, and the importance of the different stakeholders involved in the façade manufacturing and construction area.

In order to counter climate change many approaches have been taken to make
the building sector more sustainable. But for porch houses there aren't many
solutions on the market. This research project uses one of the approaches that
is does focus on porch houses, 2ndskin. In march 2018 a demonstrator project
has been build in Vlaardingen using the 2ndskin approach. The research found a
problem with integrating the installations, they took up a lot of space and were so heavy that an extra foundation was needed. This problem is not unique to 2ndskin or the zero-on-the-meter renovations of porch houses, it's a problem in other sustainable projects as well. Therefore this research has looked into the following problem:

The installations needed to renovate a post-war porch house in accordance with the 2ndskin approach are too heavy and take up a lot of valuable space.

Current systems have been analyzed in order to solve this problem. The
comparison of these systems unveiled the main causes of the size and weight
of these systems: Empty space between the installations, placement of the
connections, required space for installation and maintenance, the kind of
installations used and the integration between them. In the end three concepts
where presented. Prioritizing different aims, the concepts show different ways
to integrate the installations according to different priorities.. For the 2ndskin
demonstrator project these concepts show that its possible to decrease the by
50% to 70% and the weight by 30% to 60%. The amount of possible decrease
depends on the priorities within the project. But, smaller installations spaces are
possible when designing from within the installations instead of around it.

In the last decades, the improvement of innovative solutions on windows to achieve sustainability within the built environment is considered as a principal issue. Windows have long been used in buildings for daylight and ventilation. From many studies, health, comfort, and productivity are improved by the well-ventilated indoor environment, because ventilation dilutes the indoor concentration of contamination for indoor air quality. Also, too high indoor air velocity is perceived as draft or chilly, but too low air velocity may create stuffiness. Besides, natural ventilation is one of the most prominent issues of energy consumption within buildings. In summer, cooperated with chimney effect, natural ventilation can reduce the use of the cooling system. Even in winter, the operable window should dynamically adjust the ventilation rates based on actual population to control human CO2 emissions. Consequently, the use of heating, ventilation and air conditioning (HVAC) system will be reduced.
Windows influence the natural ventilation of a building directly and guarantee indoor comfort level, indoor air quality and minimize energy consumption. Windows can be opened manually, or center controlled mechanically. Unreachable windows for instance, in atrium or skylight, are opened by window actuators which are centrally controlled or passively controlled for the reason to optimize indoor comfort. There are advantages using window actuators in terms of controlled natural ventilation. Window actuators can make a significant contribution to a building’s indoor environment and energy performance.
Today it should be easy for the window to control opening sizes for adapting wind direction and wind load, meanwhile, the inlet air velocity should be possibly manipulated to optimize indoor air velocity. In this thesis, the dynamic way of opening windows by using window actuators for the reason of manipulating inlet wind velocity and adapting wind direction and load will be developed. Inspired by that air velocity varies on a curved surface because of curvature changing, inlet air velocity can be manipulated continuously and smoothly by changing window curvature.

The building sector is responsible for more than one third of resource consumption globally. Concerning the new construction, new regulations have been set, which impose that by 2020 all new buildings constructed within the EU should reach nearly zero-energy levels. The building envelope plays a strategic role in the energy and environmental performance of the building, significantly affecting the levels of indoor comfort. The increasing necessity of sustainability in built environments is leading to the need of the adaptive façade adoption. The façade is no longer a mere static element offering just a shelter for users. The future building skin is required to respond dynamically, being able to react to non-continuous, ever-changing climatic conditions, occupant comfort and energy efficiency requirements. It is apparent that building facades need to be transformed to fulfill adapted roles of high performance integration and façade elements need to be designed to provide the necessary flexibility needed in terms of energy flow and thermal comfort.
Companies like “Rollecate”, which is a facade construction company in the Netherlands with worldwide projects have grasped this change and are interested in creating new products, which reflect the current trend of adaptivity. This graduation project started with the existing research project “Future Adaptive Facades and Components” with the question from “Rollecate” about the direction the facade industry is heading to. “Rollecate” wants to know what the future of adaptive facades is and how this is translated into a new product or a modification of an existing one that could be developed soon and be relevant for the building sector in the next five years and on.
The aim of the research project is the development of a Multi-functional Façade Module (MFM) that consists of several functionalized layers that could be separately assembled depending on the architectural design of the building and the corresponding climate. Moreover, the proposed design is modular, which gives the possibility to be altered easily throughout its lifecycle, thus being also adaptive to future technological innovations. In order to evaluate it, this facade system is tested for an office building in Amsterdam, Netherlands with the main objective of providing thermal comfort to the occupants, whilst minimizing the energy consumption.
In the framework of a decade-long research activity on Advanced Integrated Façades (AIF), MFMs show a considerable potential for building envelopes, being one of the most promising Responsive Building Elements (RBE) in terms of energy reduction potential. In addition, the results of this research project prove that MFMs are performing well, offering considerable energy savings. They are a promising facade concept for future applications, offering not only an adaptive but also a sustainable solution to the construction of office buildings. Nevertheless, there is still space for future improvement, as well as further research and development as explained at the end of this research project.

The building sector in Europe represents 40% of the energy consumption and, of this amount, 26% is represented by office buildings that demand 44% of the energy only for lighting. Therefore, architects and engineers have a big responsibility to find design strategies and technologies that answer to this issue. In particular, a possible approach is the application of adaptive façades that respond to outdoor and indoor stimuli in order to fulfil requirements. In this research, a definition of adaptive façade will be given, and different typologies of adaptive facades will be investigated in order to understand what their future trends are. Moreover, particular attention will be given to smart windows and to daylight management strategies in order to provide a design solution that improves the visual comfort of an office space by solving glare, increasing the amount of daylight and therefore reducing the energy demand for electrical lighting. Furthermore, because of the strong correlation between visual comfort and thermal comfort - due to the fact that both of them depend on the solar radiation - the design will be further improved in order to achieve a façade that controls visible light and solar heat gain independently. This will enable to achieve the optimal configuration over the year and decrease the overall energy consumption of the building.

The main question of this master thesis is: Which changes have to be made to make the Lidl’s Specification circular, with an emphasis on materials and assembly? To come to an answer, a multitude of steps were taken.

The first step was an assessment of the principles of Circular Economy, the principles which lie at the foundation of the, Technological and Biological cycle. A number of different assessment methods were analysed on their circular implementation, they have been evaluated on five assessment criteria for the Circular Economy. The Material Circularity Indicator and the Disassembly Potential are concluded to be the most effective, especially when used in tandem. The Material Circularity Indicator is used to determine the circularity of a material used in a building component. The Disassembly Potential gives an indication how well a building can be brought back to its original materials, it determines if disassembly or demolition will be most likely. These two methods used for the next step.

This next step is the analysis of the Specification of the Lidl. The 6 S-model of Steward Brand is used in combination with both the MCI and the DP to determine the circularity of the most important components mentioned in the Specification. The components are divided into three categories, sufficient, partially sufficient and insufficient in their circularity.

As the third step, a redesign was made, to change a component from insufficient to sufficient. The roof was chosen as this component. Most of the roof components were partially sufficient, but has a lot of functionalities, which make it a broader applicable example.
In the redesign, two design were evaluated, a technical redesign and a green redesign. The technical design mainly focussed on rematerializing the original roof design so it would receive a higher MCI, the result showed that just changing materials isn’t a sufficient strategy, the design needs to enable disassembly. The green redesign instead focussed on used biological degradable materials, it fully redesigned both the materials and the connecting principles. The green redesign showed which changes were necessary to enable circularity in the Specification.

Each of the steps provided answers to main research question. The result are the following five changes:
•Exchange non-circular materials, materials which can’t be economically recycled at the end of their technical life span, for materials which can be recycled.
•Enable reuse of materials, by removing static constructions methods, making all connections reversable.
•Make dimensions and connections generic.
•Implement the criteria from the Material Circularity Indicator to the Specification for circular materials.
•The development strategy of the Lidl needs to be changed, reusing elements and components instead of employing new ones.
These recommendations are a reasonable first step on a long journey to a circular supermarket chain.

The building industry consumes a lot of energy, uses a lot of materials and generates a lot of waste. In order to achieve sustainable development, it has to change its focus from merely the use phase to the complete life cycle of buildings. The PD lab is an experimental platform that does so, by setting its aim to develop a modular and demountable building system that fits in a circular economy. In the spring of 2017, a prototype of the PD lab was built: the PD test lab. The cladding system that was applied, is made of an aluminium sandwich material, which is non-renewable, difficult to recycle and therefore not optimal for application in the circular economy. Biobased materials however are organic, renewable materials and might fit better in a circular economy.

This thesis researches the potentials of biobased materials for application as cladding material by developing a rainscreen cladding system for the PD lab. Based on a material assessment, the bio-composite material ‘Resysta’ is chosen as a starting point for the concept development. For seven aspects of the cladding system, which are: assembly, connection, horizontal joints, vertical joints, sub-construction, panel stiffness and processing technique, concepts are generated. The most suitable aspect concepts are then combined into five total concept. Initially, the total concept of extruded panels is elaborated. However, critical limitations of extrusion are encountered later on in the design process. These limitations are: open ends of the extruded panels and a processing technique which is inflexible, demands high initial investments and allows a maximum panel width of 300 milometers. Instead, the tapered panel total concept is elaborated. Based on the design problems that were found during the construction of the aluminium sandwich cladding system, special attention is given to the functions of drainage, cavity ventilation, aesthetics, assembly, space for adjustment and thermal expansion. Eventually, a biobased cladding system for the PD lab is achieved that fulfils these functions.

In order to bring the PD lab and its cladding system to the next level, further research is necessary on biobased materials, the development of critical cladding parts, processing techniques and the integration of the system in the circular economy.

Nowadays the use of renewable energy resources is a necessity. Approximately 13% of the energy spent in Greece comes from renewable energy resources, however a significantly higher percentage is essential in order to meet the European standards by 2020. A prompt solution is the in-situ energy generation. Additionally, the harmful emmisions of the various air-conditioning and refridgerating systems need to be eliminated. The current master thesis involves the use of solar energy for indoor temperature regulation, mainly for cooling purposes. This is achieved by the use of two different technologies; the photovoltaics and the thermoelectrics. A series of PV panels convert the solar energy to DC power, which is supplied to the thermoelectric devices. The TE modules are able to create temperature difference and depending on the direction of the DC current, they can function either for cooling or for heating. The system is 100% emission-free and can operate entirely on renewable energy. Location of the project is set to Athens, Greece, a city with rather high air-conditioning demands during summer and high solar irradiation all year long, traits which make it very favorable for a PV-TE solar cooling application. Objective of the thesis is to develop a solar cooling facade concept which, along with the implementation of passive design strategies, is able to cover the cooling and heating demands of a certain office space. Considering the context, the local climate, the prominent vernacular building strategies have been studied. Moreover, a field research and analysis of 25 case study buildings has been carried out leading to the definition of the ‘typical office building’ in Athens. Based on the typical office, a passive optimization with the implementation of multiple passive strategies has been carried out resulting in the optimum scenario. The PV and TE system has been calculated and designed according to the optimum passive scenario and is applied on a case-study building. A range of architectural possibilities is explored, based on the typical office buildings of the area.

This research is primarily aimed at getting to know the material. Thin-glass is a product of recent developments within the glass-production industry, which has not yet found its place in the building industry. The material is still undergoing innovative changes to adapt it for use in various applications. We have not yet visualized or researched how it could influence architecture.
The combination of thin-glass and wood appears to bring out the best qualities of both materials as they compliment each other with essential qualities required for building constructions. Their ability to bend and tolerate stresses opens up new possibilities for use in architecture. This enables us to experiment and create new light-weight structures in a variety of forms.

In de Paris Climate Agreement the goal is set to reach an energy neutral built environment by 2050. As a result, there is a high demand for energy neutral refurbishment of the existing housing stock. With the currently low refurbishment rate is it expected to take around 250 years to reach this goal. Due to the high initial investment costs of refurbishment, spread out over a short period of time, replacement and rebuilding is often the preferred option, while refurbishment is significantly less material consuming. Still the environmental impact of a refurbished building appears to be similar to the environmental impact of a new building, when looking at the material use spread out over the lifetime.

The Circular Economy is a solution to the problem of the current linear lifecycle of refurbishment, because it strives for an increased lifetime of the refurbishment by enabling reuse of components at the end of their functional service life and recycling of materials at the end of their technical service life. The Circular Economy aims to close and extend the loops of material cycles, in order to preserve value of materials, resulting in decreased raw material consumption and waste generation.

In this research the level of circularity of the 2nd Skin Façade Refurbishment system, which is a refurbishment strategy that wraps the building into a second layer of insulation, is examined. The level of circularity of the materials as well as the disassembly potential of the connections between the components and materials, have been analysed. Based on the assessment results, a Roadmap for circular façade refurbishment is developed. As validation of the approach, a design proposal is made for the Circular 2nd Skin Façade Refurbishment system, which is a universal refurbishment system that can be applied to different residential building typologies. The system is designed for future changes, as it enables reconfiguration of the façade arrangement and disassembly at the end of its functional lifetime. Instead of ending up as unrecoverable waste, the circular façade refurbishment system can be reused multiple times for the refurbishment of other residential buildings, exploiting the technical lifetime of the materials to the fullest.

The demolition activities produce a huge amount of waste that have negative effects on the environment. In the current demolition practices, most of the waste are recycled or landfilled. Only a small percentage is retrieved and reused again. Reuse is preferred than recycling since it better for the environment. To increase the reuse, more materials need to become available from the demolition activities. To current demolition process does not enable the retrieval of components and materials for reuse since they are damaged in the process, and the demolition contractors don’t make an effort to retrieve them properly. This thesis investigated the demolition process and how its steps and the actors involved could affect the reuse potential of components and materials in the building industry. To find answers, literature study, a case study and expert interviews with frontrunners were used. The best practices from the Netherlands were taken as an input in order to develop the new process. Based on the findings, a flowchart of the new demolition process is developed, and recommendations are given to the actors involved. Changes are proposed in the five stages (tender, audit, planning, execution, materials handling) of the demolition process and to the actors involved. Sustainability tender criteria, site visits, detailed inventory, buyers through the network, deconstruction, separation in different material streams are some of the changes that need to be made. By adopting the proposed changes the actors involved could retrieve a lot more components and material from the demolition sites and provide them for reuse.

Building Integrated Photovoltaics (BIPV) has the potential to play a major role in the ongoing transition towards nearly zero energy buildings. However, the BIPV market is still a niche market, representing only 1% of the global PV share. One of the main barriers that hinder the deployment of BIPV is the lack of aesthetic flexibility. Architects and designers are often reluctant to embed PV systems in buildings due to their unsuitable color.
In this thesis, the use of interference filters (IFs) as color coating solution for PV modules is proposed. IFs are optical devices designed to selectively reflect a narrow portion of the visible solar spectrum while transmitting the remaining part. The structural coloration provided by the filter is highly dependent on the angle of incidence of the light. This angular dependence could be an issue for BIPV applications, since color homogeneity is often an important requirement. The objective of this work is to model, fabricate and assess the opto-electrical performance of colored crystalline silicon (c-Si) PV modules based on interference filters, with the final goal of increasing the aesthetics of this technology.
First, the angular resilience challenge is addressed. Simulation results show that texturing the glass surface significantly improves the color stability, thanks to diffuse reflection of light. Very high angular resilience up to 80º can be achieved with a double-side texture profile made of hemispherical grooves. Secondly, five interference filters deposited on different glass substrates are used to fabricate 10 x 10 cm² c-Si colored mini-modules. The optical characterization of the demonstrators
allows to partially validate the optical model and confirm the good angular resilience of the textured surfaces. Finally, the electrical performance of the mini-modules is evaluated. I-V measurements show that IFs only affect the short-circuit current of the mini-modules due to optical losses. Depending on the color and the topology of the surface, absolute efficiency losses range from 0,95% to 4,6%.