Neighbourhoods in Transition

This open access book is focused on the intersection between urban brownfields and the sustainability transitions of metreopolitan areas, cities and neighbourhoods. It provides both a theoretical and practical approach to the topic, offering a thorough introduction to urban brownfields and regeneration projects as well as an operational monitoring tool. Neighbourhoods in Transition begins with an overview of historic urban development and strategic areas in the hearts of towns to be developed. It then defines several key issues related to the topic, including urban brownfields, regeneration projects, and sustainability issues related to neighbourhood development. The second part of this book is focused on support tools, explaining the challenges faced, the steps involved in a regeneration process, and offering an operational monitoring tool. It applies the unique tool to case studies in three selected neighbourhoods and the outcomes of one case study are also presented and discussed, highlighting its benefits. The audience for this book will be both professional and academic. It will support researchers as an up-to-date reference book on urban brownfield regeneration projects, and also the work of architects, urban designers, urban planners and engineers involved in sustainability transitions of the built environment

Integrated design strategies for renovation projects with building-integrated

As tomorrow’s cities are already largely built, and as many of their buildings have a low energy performance level, urban renewal processes are essential for the sustainable development of European cities. In this context, Building-Integrated Photovoltaic (BIPV) systems, using innovative PV products as new construction material for façades and roofs, can potentially provide a crucial response for achieving long-term carbon targets. This paper presents an integrated architectural design process for addressing renovation projects. Presented through a comparison of two case studies on archetypal residential buildings from the 1900s and 1970s in Neuchâtel (Switzerland), this approach includes the design of different renovation scenarios integrating passive, active and BIPV strategies. An optimization of the potential BIPV (or active) surfaces based on the annual irradiation threshold is conducted to maximize self-consumption (SC) and self-sufficiency (SS). The scenarios, before and after this optimization-based refinement, are evaluated in terms of Life-Cycle Assessment and Cost. Results demonstrate the importance of the optimization to ensure the cost-effectiveness of the strategy and increase the independence from energy suppliers. The main outcome provides, to architects and engineers, advanced BIPV renovation strategies along with results from a multi-criteria evaluation that are crucial for reaching carbon neutralityPostprint (published version

Active surfaces selection method for building-integrated photovoltaics (BIPV) in renovation projects based on self-consumption and self-sufficiency

In light of the Paris Agreement's objectives and the related European and Swiss goals of decarbonising the built environment, the importance, relevance, and potential benefits of integrating Building-Integrated Photovoltaic (BIPV) within building renovation processes are acknowledged. Functioning both as envelope material and on-site electricity generator, BIPV can simultaneously reduce the use of fossil fuels and greenhouse gas emissions. Motivated by the current barriers and misconceptions that withhold a widespread integration of BIPV, particularly regarding financial implications and solar exposure levels that are believed to be unfavourable, this paper aims at bringing new knowledge and a rigorous and adaptable method to inform decision-making and promote the use of BIPV in urban renewal processes. Focusing on the architectural design, we here present a methodology to select active (BIPV) surfaces during the retrofitting process based on a trade-off between the self-consumption (SC) and self-sufficiency (SS) of a building. The approach consists in iteratively identifying surfaces that achieve a varying annual irradiation value (threshold). It also includes the evaluation of the effect of electricity storage systems. The methodology and the results of its application are presented through the comparison of two case studies in Neuchâtel (Switzerland). The outcomes of this new approach for addressing building renovation projects in the urban context can help architects, designers and engineers to better size the installation and the repartition of active surfaces in the renovated thermal envelope. Results show that it is important to take into account a larger range of irradiation levels to choose the active surfaces, especially in high-rise buildings with a greater proportion of façade than roof. In such cases, the irradiation threshold can vary between 600 and 800 kWh/m2•year depending on the strategy adopted in terms of Heating, Ventilation and Air-conditioning (HVAC) system improvement or storage system implementation. Such findings demonstrate the need for context-specific methods towards a proper evaluation and better valorisation of BIPV potential.Peer ReviewedPostprint (author's final draft

Architectural design scenarios with building-integrated photovoltaic solutions in renovation processes: case study in Neuchâtel (Switzerland)

In view of the importance of urban renewal processes, building-integrated photovoltaic (BIPV) systems can potentially provide a crucial response to the energy turnaround challenges. Functioning both as envelope material and electricity generator, they can simultaneously reduce the use of fossil fuels and greenhouse gases emissions while providing savings in materials and electricity costs. However, despite continuous technological and economic progress, the assets of BIPV remain undervalued in the current practice. Various obstacles (technology choice, small volumes, lack of information and good examples) tend to increase the costs and reduce the project acceptance. To overcome these barriers, an interdisciplinary research project developed an approach based on four main phases: 1) selection of archetypal residential buildings, 2) detailed analysis of the buildings, 3) development of renewal design scenarios and 4) multi-criteria assessment of each scenario. Focusing on the architectural-scale, this paper presents design strategies with BIPV solutions of a representative case study realized in Neuchâtel (Switzerland). A multi-criteria assessment of the proposed design scenarios allows comparing the different strategies. It highlights the influence of the design decisions on the final performances, helping us to move towards an optimization of the BIPV surfaces in order to maximize self-consumption regarding the building consumption profile.Postprint (published version

Influence of design-decisions on the energy performance of renovation projects with building-integrated photovoltaics: results for a 1968 residential archetype in Neuchâtel (Switzerland)

The renovation of existing buildings is one of the priorities of western countries and needs to be promoted to increase the current low renovation rate, estimated to be of 0.6% per year in the European and Swiss contexts. In parallel, the implementation of building-integrated photovoltaic (BIPV) elements during the renovation process can provide a crucial response to achieve the 2050 targets in terms of greenhouse gas (GHG) emissions and energy savings. In this context, architects, designers and engineers have a key role in achieving these objectives, mainly because they are responsible for the design decisions during the development of the projects, especially during the early-design phase when the most influential decisions are taken. Through a real-case study built in 1968, this research shows how certain design-decisions in renovation processes can affect or compromise the final performance of the building from a global life-cycle and multi-criteria approach. Life-Cycle Analysis (LCA) and Cost (LCC) results show the importance of not losing the opportunity to go beyond current practices when a building needs to be renovated and highlight the necessity to take into consideration BIPV strategies to guarantee both economic and environmental targets.Postprint (published version

Towards integrated design strategies for implementing BIPV systems into urban renewal processes: first case study in Neuchâtel (Switzerland)

In view of the importance of urban renewal processes, building-integrated photovoltaic (BIPV) systems can potentially provide a crucial response to the challenges of the energy turnaround. Functioning both as envelope material and electricity generator, they can simultaneously reduce the use of fossil fuels and greenhouse gases (GHG) emissions while providing savings in materials and electricity costs. These are precisely the objectives of most European energy directives, from zero- to positive-energy buildings. In Switzerland for instance, one way to achieve the objectives of the “Energy strategy 2050” is to install PV systems to cover 1/3 of the annual electricity demand. However, despite continuous technological and economic progress, the significant assets of BIPV remain broadly undervalued in the current practice. Various obstacles (technology choice, small volumes, lack of information and good examples, etc.) tend to increase the costs and reduce the acceptance of BIPV solutions. The present paper is an integral part of an interdisciplinary research project. Focusing on the architectural design issues, it presents the first results of a representative case study carried out in the city of Neuchâtel (Switzerland). The approach involves four main phases (Fig.1): (i) archetypes identification, (ii) building detailed analysis, (iii) development of architectural renewal design scenarios, and (iv) multi-criteria assessment of each scenario (energy consumption, electricity production, cost-effectiveness, and Life-Cycle Analysis). The application of the proposed approach on a case study allows us to initiate the first step towards a holistic and reliable multi-criteria comparison methodology for BIPV-adapted solutions in urban renewal design processes in the Swiss context.Peer ReviewedPostprint (published version

Comparison of strategies improving local energy self-sufficiency at neighborhood Scale. Case study in Yverdon-les-Bains (Switzerland)

Within a context of growing efforts to develop sustainability strategies, one of the main challenges is promoting value creation while using fewer resources. In this perspective, how can we design attractive urban neighborhoods generating endogenous economic activity and fostering socio-cultural dynamics, while moving towards local energy self-sufficiency? Answering that question requires major changes in the way we consider energy in the construction sector, by thinking beyond the scale of a single building and by including a greater number of design parameters. Filling this gap in current research, the Symbiotic Districts project examines dimensions influencing energy self-sufficiency at neighborhood scale by integrating parameters related to buildings, infrastructure, mobility, food, goods and services. The present paper analyzes the results of a case study on an urban sector in the city of Yverdon-les- Bains (Switzerland). Taking lifestyles as a starting point, the project explores three scenarios (technological, behavioral and symbiotic) for the future development of this neighborhood for 2035. The scenarios test different design strategies related to industrial symbioses, production, storage, transportation or urban agriculture. In order to calculate an estimated global balance, an energy flow analysis allows the assessment and comparison of the energy performance of each scenario. In parallel, an urban form adapted to the proposed vision evaluates how architectural and urban design is likely to foster the necessary behavior changes towards the expected energy turnaround

GREEN DENSITY. A Transdisciplinary Research and Teaching Project for the Design of Sustainable Neighbourhoods

The GREEN DENSITY transdisciplinary research and teaching project focuses on the Waldstadt sector, a strip of forest bordering the city of Bern. This strategic site, likely to host new inhabitants and jobs close to public transport, is particularly adapted to explore urban densification issues. The objective is to experiment, compare and evaluate diverse possible urban forms for the development of such a site. The process includes the elaboration of six urban and architectural visions from students’ projects developed within Rey’s studio at Ecole polytechnique fédérale de Lausanne (EPFL) and their transdisciplinary multi-criteria assessment

GREEN DENSITY - Exploration multidimensionnelle de nouvelles polarités urbaines

Face aux multiples conséquences induites par l’étalement urbain, un consensus se dégage progressivement pour réorienter le développement du bâti vers l’intérieur et pour favoriser les processus de densification urbaine. Dans ce contexte, les sites susceptibles d’accueillir de nouveaux habitants et emplois à proximité des transports publics acquièrent un statut particulièrement stratégique. Le site de Waldstadt, sur lequel a porté le projet de recherche et d'enseignement GREEN DENSITY, constitue un champ d’investigation particulièrement adapté à l’exploration des multiples enjeux induit par la création de nouvelles polarités urbaines. La démarche consiste en l'élaboration et l'évaluation de six visions urbaines à partir des travaux d'étudiants réalisés au sein de l'atelier du Prof. Emmanuel Rey. Par des approches complémentaires, elles visent à expérimenter, comparer et évaluer diverses formes urbaines envisageables pour le développement d’un tel site

An Operational Indicator System for the Integration of Sustainability into the Design Process of Urban Wasteland Regeneration Projects

In the context of sustainable development of European post-industrial cities, urban wastelands offer an important potential of surfaces to recapture. The regeneration of these sites is indeed an opportunity to simultaneously create density within the existing built fabric and revitalize some portions of cities and metropolitan areas. Although the launching of several initiatives of this type can be observed, their implication toward sustainable development is in most cases implicit and superficial. In point of fact, integration of sustainability into urban wasteland regeneration projects cannot be summarized by a mere density issue. It requires a proactive search for global quality, implemented in a participative way into the project dynamics, and a continuous monitoring of environmental, social and economic dimensions adapted to such projects. Specifically addressing these considerations, this paper introduces the development of an operational indicator system for the integration of sustainability into the design process of urban wasteland regeneration projects. It aims to provide a tool for structured and continuous evaluation, hinged on their specific characteristics, and to give useful basis to stakeholders involved in their management. Subsequently, the paper presents a first test application performed on a project underway in Switzerland, which validates its usability. Further work suggests the integration of the system into a digital monitoring tool in order to make it applicable to a variety of projects of this type