Design for deconstruction : emergy approach to evaluate deconstruction effectiveness

Tese de doutoramento em Arquitectura - Projecto e Tecnologias da ConstruçãoRecovery of materials is a crucial concern to avoid depletion of natural resources nowadays. Industrial Ecology recognised the role of industrial activities in order to minimise waste flows and to maximise materials and components recovery, by means of reuse and recycling. Construction industries, however, is slowly becoming aware of building materials recovery and at present new approaches are seriously examined such as Design for Disassembly/Deconstruction (DfD). Furthermore, in order to evaluate the building deconstruction several approaches can be employed. In this research work the Emergy approach (spelled with an “M”) is considered to be a more effective tool for such evaluations. This approach looks beyond the technosphere and takes into account the role of our planet as the sole source of materials and the largest recycler of material ´s life cycle. Principles and practices of Design for Disassembly from car and electronics industries are examined and their applications provide avenues of development for construction industry. Using principles of DfD and Emergy theory, a model to measure the environmental net benefit of building materials recovery at the design stage is proposed. The model estimates the Deconstruction Effectiveness index (DE) of a building and enables designer to compare the alternative options, selecting the optimum solution. By introducing the idea of ‘effectiveness’, rather than ‘efficiency’, the model describes the balance between the resources that are consumed in a building or building element, and the amount of non-extracted resources due to their reuse or recycling. The model analyses the building design and estimates an index that expresses the quantitative environmental net benefit of building materials recovery. This index considers the materials that are saved by materials recovery and the input of materials during the Lifespan of a building or building element. Thus, it may be used also as a reference for improvement of the solution at the design stage with regards to the feasible end-of-life scenarios that maximise materials recovery. The proposed model is composed by the following steps: (1) analysis of technological building configuration, (2) accounting for the flows within the building system, (3) estimating the DE index, and (4) solution improvement. The DE index varies between 0 and 1, for buildings with no recovered materials (DE=0) and buildings that are reused totally (DE=1). For the assessment of the model, three different internal walls (brick masonry, plasterboard, and wood frame), and three different construction systems (concrete, steel, and wood) were used. Results obtained indicated that DE varies between 0.25 and 0.59 for different wall systems evaluated, while, for different building systems varies between 0.30 and 0.51. The better result is due to plasterboard disassemblability properties and high Emergy per mass of materials used, which benefits this option due to the raw materials that are saved. Results obtained from the application of DE index to buildings are also influenced by the disassemblability of the construction systems, the Emergy per mass of the materials, and the feasible end-of-life scenarios. The application of Deconstruction Effectiveness to these case studies highlights the model’s sensitivity to the disassembly properties of buildings, materials durability, end-of-life scenarios, and the environmental value of materials for which the recovered materials are a substitute. Application of the DE index to building design meets the DfD principles, enhances the quality of the recovered building materials and the environmental value of those materials in which nature made the greatest investments, i.e. non-renewable resources, provided by longer natural cycles and higher energy flows.Actualmente, a recuperação dos materiais é uma preocupação crucial para evitar a exaustão dos recursos naturais. A Ecologia Industrial reconhece o papel das actividades industriais na minimização dos fluxos de resíduos e na maximização da recuperação de materiais e componentes, por meios de reutilização ou de reciclagem. Nas actividades da construção, no entanto, começa-se lentamente a tomar consciência da necessidade da recuperação dos materiais de construção e, no presente, novas abordagens são estudadas e apresentadas, como a Concepção para a Desconstrução. No entanto, de modo a avaliar a desconstrução de edifícios, um conjunto de diferentes abordagens pode ser empregue. Neste estudo a teoria da Emergia (escrita com “M”) é considerada como sendo uma ferramenta mais efectiva para tais avaliações. A abordagem da Emergia está para além da tecnosfera e tem em conta o papel do nosso planeta como sendo a única fonte de materiais e o maior sistema de reciclagem no ciclo de vida dos materiais. Princípios e práticas da Concepção para a Desconstrução nas indústrias de produção de automóveis e produtos electrónicos, bem como a sua aplicação, fornecem igualmente linhas de orientação para a indústria da construção. Através da aplicação dos princípios da concepção para a desconstrução e da teoria da Emergia, é proposto um modelo para estimar o benefício da recuperação dos materiais de construção. O modelo estima o índice de Efectividade da Desconstrução (ED) de um edifício e permite que o projectista compare soluções alternativas, escolhendo a solução optimizada. Através da ideia de “efectividade”, em vez de “eficiência”, o modelo descreve assim o equilíbrio entre os recursos que são consumidos num edifício ou elemento do edifício, e a quantidade de recursos que não são extraídos devidos à sua reutilização ou reciclagem. O modelo analisa a concepção do edifício e estima um índice que expressa quantitativamente o benefício ambiental da recuperação dos materiais de construção. O índice considera os recursos que são poupados pela recuperação de materiais e o fluxo de materiais durante o tempo de vida de um edifício ou elemento da construção. Assim, o modelo poderá ser também uma referência para a melhoria das soluções durante a fase de concepção, tendo em conta os cenários de fim de vida mais viáveis para a maximização da recuperação dos materiais. O modelo proposto é composto pelos seguintes passos: (1) análise da configuração tecnológica do edifício, (2) estimativa dos fluxos que atravessam o sistema do edifício, (3) cálculo do índice ED e (4) melhoria da solução. O índice ED varia entre 0 e 1, sendo ED=0 para edifícios sem possibilidade de recuperação de materiais e sendo ED=1 para edifícios cujos materiais serão totalmente reutilizados. Para a avaliação do modelo, foram utilizados três tipos de paredes interiores (alvenaria de tijolo, gesso cartonado, e madeira) e três tipos de sistemas de construção (betão armado, aço e madeira). Os resultados obtidos indicam que ED varia entre 0.25 e 0.59 para os diferentes tipos de paredes interiores avaliadas e que ED varia entre 0.30 e 0.51 para os diferentes tipos de sistemas construtivos. O melhor resultado obtido pela parede de gesso cartonado reflecte as suas propriedades de desmontagem e os elevados valores de Emergia por massa dos materiais empregues, o que beneficia esta opção em comparação com os recursos que são salvos. Os resultados obtidos da aplicação do índice ED aos edifícios são igualmente influenciados pela facilidade de desconstrução dos sistemas, a Emergia por massa dos materiais e a viabilidade dos cenários de fim de vida. A aplicação da Efectividade da Desconstrução aos casos de estudo evidencia a sensibilidade do modelo às propriedades de desconstrução dos edifícios, durabilidade dos materiais, cenários de fim de vida e, inclusive, ao valor ambiental dos recursos para os quais os materiais recuperados são substitutos. A aplicação do índice ED à concepção dos edifícios observa os princípios da Concepção para a Desconstrução e o valor ambiental dos materiais nos quais a natureza fez os maiores “investimentos”, i.e. recursos não renováveis, providos por longos ciclos naturais e grandes fluxos de energia.Ministério da Ciência, Tecnologia e Ensino Superior - Programa Operacional Ciência e Inovação 201

Conservación de recursos a través de estrategias de reutilización de edificios y de reutilización de materiales en el sitio

Rethinking buildings and construction activities is a fundamental step towards sustainable construction. Being one of the most materials consumers, changes to current practices in the construction industry are crucial in order to effectively reduce primary resources exploitation, as also to reduce the environmental impacts associated with it. End of life of buildings are opportunities to close the materials loop, by means of building renewal and recovery of components and materials. In this context, building reuse and on site materials reuse have shown to be the most preferable end of life scenarios when compared with off site reuse, recycling, energy recovery and landfill disposal. Moving from demolition to deconstruction is one of the changes that are supposed to happen. Another is to change the materials selection procedures in order to consider also reused materials as a valid option in architectural process. Therefore, surveys to assess reuse potential are needed prior to architectural design in order to look for reuse opportunities and reuse constrains both at the building level and materials level. Such opportunities and constrains comprise building adaptability, building conservation state, mechanical and aesthetic performance of materials, feasibility of components and materials recovery. However, existing buildings were not built to be deconstructed and materials recovery is a labor intensive task, facing obstacles as non reversible connections which usually destroy materials integrity. A case study for building reuse and on site materials reuse is here analised in order to illustrate the theoretical principles and goals that drive the reuse approach, highlighting the environmental benefits by keeping Embodied Energy and thus reducing the Global Warming Potential related to construction activitiesRepensar los edificios y las actividades de la construcción es un paso fundamental hacia la construcción sostenible. Siendo uno de los mayores consumidores de materiales, es crucial proceder a cambios en las prácticas actuales en el sector de la construcción para reducir efectivamente la explotación de recursos primarios, como también para reducir todos los impactos ambientales asociados. El fin de vida de los edificios son oportunidades para cerrar el ciclo de vida de los materiales, por medio de la renovación de los edificios y la recuperación de componentes y materiales. En este contexto, la reutilización de los edificios y la reutilización de los materiales en el sitio han demostrado ser la solución más preferible en la gestión de los escenarios de fin de ciclo de vida, en comparación con la reutilización de los materiales fuera del sitio, reciclaje, valorización energética y eliminación en vertedero. Pasar de la demolición a la deconstrucción es uno de los cambios que deberá de acontecer. Otro es lo de cambiar los procedimientos de selección de los materiales con el fin de tener en cuenta también los materiales reutilizables como una opción válida en el proyecto arquitectónico. Por lo tanto, se necesita estudiar el edificio para evaluar su potencial de reutilización antes del proyecto, con el fin de buscar oportunidades y restricciones a la reutilización, tanto al nivel del edificio como al nivel de los componentes y materiales. Tales oportunidades y limitaciones incluyen la capacidad de adaptación del edificio, su estado de conservación, el funcionamiento mecánico y condición estética de los materiales y, por fin, la viabilidad técnica y económica de la recuperación de esos componentes y materiales. Sin embargo, los edificios existentes no fueron construidos para seren deconstruidos y la recuperación de materiales se torna una tarea intensiva de trabajo, enfrentando obstáculos como conexiones no reversibles que normalmente destruyen la integridad de los materiales. Un caso de estudio para la reutilización de la construcción y la reutilización de materiales en el sitio está aquí analizado con el fin de ilustrar los principios y objetivos teóricos que impulsan el enfoque de la reutilización, destacando los beneficios ambientales al mantener la energía incorporada y reduciendo así el potencial de calentamiento global relacionado con las actividades de construcción

Revealing the World Heritage cities and their varied natures

Mankind gets impoverished every time cultural and natural heritage gets irreversibly destroyed. World Heritage cities host cultural heritage of "outstanding universal value"; so, the destruction of their cultural heritage brings higher impoverishment than on any other city. Development is not the only threat found endangering WH cities, but is one of their most prominent and rising threats. Though, cities need to keep evolving and no development can strongly compromise their sustainability. Reacting upon the cun'ent lack of an updated list of WH cities, this article proposes a definition and reveals the respective list, distinguished according to their varied natures. These results will allow further research to verify if the nature of WH cities is an influencing factor on their endanger level

Connections and joints in buildings: Revisiting the main concepts on building materials life cycle’s circularity

Joining methods were set as a field of study and the state of the art on connections in buildings within building materials circularity was reviewed. The cross reference of fields of connections in buildings and resources and waste management has highlighted a set of constraints for implementing circularity strategies such as reversibility of connections: the gap between existing systematisation of knowledge on connections in buildings and the strategies and guidance to support their design, the divergent conclusions reached resulting from partial approaches on circularity and its strategies and, lastly, the questions raised by the consequences of adopting reversible solutions that are still open for discussion.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 642384.The authors acknowledge the Portuguese Foundation for Science and Technology for the financial support under Reference SFRH/BD/79082/2011

Sustainable Building 2007, Sustainable Construction, Materials and Practices, Challenges for the New Millennium

The international conference “Portugal SBO7: Sustainable Construction, Materials and Practices - Challenge of the Industry for the New Millennium” is organised in the scope of the International Initiative for Sustainable Built Environment (iiSBE). This event is supported by the Portuguese Presidency of the European Union during the second half of 2007 and by a range of international organisations such as CIB, IJNEP, SD-MED and COST / European Science Foundation. This international conference is part of the SBO7 regional/national event series and as such constitutes also a preparation for the 2008 World Sustainable Building Conference to be held in September 2008 in Melbourne, Australia. The venue of this conference is also relevant, as it is the first international conference on this topic to be held in Portugal. The organisers hope that this initiative will promote further the sustainability of construction industry and the built environment, consequently, contributing to further sustainable development of Portugal and the other participating countries. The construction industry is a vibrant and active industry representing approximately 10% of Portuguese GDP. The building sector is responsible for creating, modifying and improving the living environment of humanity. On the other hand, construction and buildings have considerable environmental impacts, consuming a significant proportion of limited resources of the planet including energy, raw material, water and land. Therefore, the sustainability of the built environment, the construction industry and the related activities is a pressing issue facing ali stakeholders in order to promote Sustainable Development. The new millennium is challenging practitioners and researchers with the sustainability of the built environment and the construction industry. Hence, the main purpose of this conference is to discuss these challenges and look for solutions that actively facilitate and promote the adoption of policies, methods and tools to accelerate the movement towards a global sustainable built environment. The intention of the organizers is to give an opportunity to practitioners, academics, scientists, engineers, architects, contractors, manufacturers, owners and users from all over the world to come together in a pleasant location to discuss recent developments in the field of sustainable construction, materials, practices and construction sustainability assessment. The conference main topics cover a wide range of up-to-date issues and the contributions received from the delegates reflect critical research and the best available practices in the Sustainable Construction field. The issues presented include: Building sustainability assessment tools Indoor environment quality and benchmarks Sustainable resources and materials use Use of non-conventional materials Use of industrial waste Eco-materials and technologies Sustainable management of existing building stock Innovative sustainable construction systems Design for climate change Design and technologies for energy efficiency and conservation Design for minimizing and using construction and demolition waste Design for service-life Design for deconstructionCib, iiSBE, UNEP, Cost, SD-MED, Ordem dos Engenheiro

The cultural significance of World Heritage cities: Portugal as case study

World Heritage cities are at the highest level of cultural significance, as their significance has been acknowledged of Outstanding Universal Value for the whole mankind. This recognized value needs to be kept monitored while managing the development of the city. Otherwise, local authorities might not be able to prevent it from being irreversibly damaged, and removed from the WH list. To be able to monitor the Outstanding Universal Value of their cities, local authorities need to have a clear understanding of what defines the Outstanding Universal Value, which being a broad notion of various interpretations, its definition often relies on the chosen selection criteria and justification for nomination. Value-based assessment has a deep influence on how authorities protect and preserve their World Heritage properties. Thus, the identification of the values that define the significance of a property can be most crucial to help monitoring the significance and achieve a better management

Enhancing the Outstanding Universal Value assessment practices of Willemstad

Like any other city, World Heritage (WH) Cities have a constant need for development. The challenge is to accommodate the needs of society without compromising their cultural significance, without compromising their Outstanding Universal Value (OUV). New interventions in architecture and urban development and the absence of dynamics pressure properties inscribed at the WH list. These dynamics bring new challenges to urban heritage conservation, especially because instead of enhancing, these developments are often jeopardizing the OUV of WH Cities.In order to reconcile the development and conservation of these protected zones, their potential impact on the OUV needs to be assessed in a more systematic and objective manner. This paper proposes enhancements to the OUV assessment practices undertaken at the WH City ofWillemstad, Curayao, Netherlands Antilles, by revealing the management process, the cultural values and significant attributes, as well as, its current threats.