Choix équilibré d'un isolant thermique, comment répondre aux exigences de performances énergétiques tout en limitant l'impact environnemental global et en favorisant la circularité des matières?

peer reviewedAu vu des enjeux relatifs à la rénovation énergétique du parc bâti et à la gestion des ressources, il devient urgent d’élargir le processus de sélection des matériaux isolants à des critères environnementaux et circulaires, en dépassant les préoccupations énergétiques et financières actuelles. Cette approche est mise en avant dans un état des lieux réalisé par les deux autrices sur une cinquantaine de matériaux. Elle se veut multicritère et complémentaire à l’approche quantitative de l’analyse de cycle de vie. Le présent article discute certaines notions de cet état des lieux dans l’objectif d’aider tout concepteur à faire un choix d’isolant qui soit équilibré entre ces différents aspects et adapté à son projet de rénovation13. Climate action11. Sustainable cities and communitie

How can the energy retrofitting of historic and traditional residential buildings be supported, based on the reflective process of the standard EN 16883? Decision-making tools provided by the “P-Renewal” research project

peer reviewed11. Sustainable cities and communities13. Climate actio

Quel avenir pour les logements d’avant-guerre à valeur patrimoniale en Wallonie ?

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Quel avenir pour les immeubles de bureaux du quartier européen ? Comparaison de plusieurs scénarios : une rénovation en bureaux, une reconversion en logements et une démolition-reconstruction en bureaux ou en logements

Résumé. Du point de vue environnemental, il semble évident que la rénovation des bâtiments existants constitue une issue plus favorable que la démolition-reconstruction. Cependant, encouragés par les intérêts économiques et financiers, la promotion immobilière favorise encore massivement la construction de surfaces neuves. Ce choix pose question pour les politiques de développement de nos villes qui possèdent un important parc d’immeubles de bureaux en attente de nouvelles occupations. L’enjeu est d’autant plus grand dans les quartiers monofonctionnels, comme le quartier européen à Bruxelles où les projets de bureaux neufs sont toujours très attractifs. Ces projets souvent menés sans qu’une vision à long terme n’ait préalablement fait consensus ont, en outre, des impacts conséquents, et parfois irréversibles, sur l’identité du lieu et ses valeurs d’origine. Cet article se base sur une étude de cas visant à estimer les émissions de gaz à effet de serre sur le cycle de vie d’un immeuble de bureaux, ainsi que les coûts financiers et fiscaux des interventions en considérant plusieurs scénarios de rénovation et de démolition-reconstruction. À la lumière des résultats de cette étude, il s’agit d’envisager le devenir de ces immeubles en intégrant dans la réflexion les implications architecturales et sociétales. Abstract. From an environmental point of view, it seems clear that the renovation of existing buildings is a more favourable outcome than demolition-reconstruction. However, encouraged by economic and financial interests, property developers still massively favour the construction of new buildings. This choice raises questions for the development policies of our cities, which have a large stock of office buildings awaiting new occupancy. The challenge is all the greater in monofunctional districts such as the European Quarter in Brussels, where new office projects are still very attractive. These projects, which are often carried out without any long-term vision, also have a significant and sometimes irreversible impact on the identity of the site and its original values. This article is based on a case study aimed at estimating the greenhouse gas emissions over the life cycle of an office building, as well as the financial and fiscal costs of the interventions by considering several renovation and demolition-reconstruction scenarios. In the light of the results of this study, the aim is to consider the future of these buildings, taking into account the architectural and social implications

Vers une dynamique d'objectivation de l'évaluation patrimoniale

Résumé. Le concept de valeur semble posséder une importance capitale, à la fois dans la littérature scientifique et dans le discours professionnel des différent·es acteurs et actrices du patrimoine. Les actions menées pour faire évoluer l'environnement construit hérité des générations passées semblent dépendre de la valeur que nous lui accordons. Dans le présent essai, les concepts de valeur, d'évaluateur·trice et d'évaluation patrimoniale sont discutés. Après un retour sur leurs étymologies, deuxcontextes historiques sont comparés : l'axiologie classique du XIXe siècle fondée sur la recherche de rationalité des Lumières et les typologies de valeurs contemporaines aux prises avec la complexité. Ce retour historique montre une complexification et une multiplication des grilles d'évaluation, ainsi que la nécessité de questionner la subjectivité inhérente aux prises de décisions des acteurs et actrices du patrimoine. Pour ne pas sombrer dans une forme de relativisme excessif décrédibilisant définitivement toute tentative d'objectivation des processus d'évaluations patrimoniales, un modèle dynamique de grille d'évaluation est proposé.Abstract. The concept of value seems to have capital importance both in scientific literature and in various heritage actors' professional discourse. The actions undertaken to develop the built environment inherited from previous generations seem to depend on the value we assign it. In this essay, the concepts of value, assessor, and heritage assessment are discussed. After an examination of their etymologies, two historical contexts are compared: the classical axiology of the 19th century based on the Enlightenment search for rationality and the typologies of contemporary values struggling with complexity. This historical reassessment shows a complexification and multiplication of evaluation grids, as well as the need to question the subjectivity inherent in heritage actors' decisions. In order not to sink into excessive relativism definitively discrediting any attempt to objectify the process of heritage assessments, a dynamic evaluation grid model is proposed

A method for the retrofitting of pre-1914 Walloon dwellings with heritage value

The sustainable energy renovation of historical buildings and listed heritage is a challenge for Belgium and other European countries. These are crucial for urban and rural development and for the future of old buildings. This is the context of the ‘P-RENEWAL’ research project. It aims to develop a methodological tool for retrofitting historical Walloon dwellings built before 1914, to enhance their heritage values while implementing relevant energy measures. The originality of this research is to consider energy, environmental and heritage aspects in a complementary way, in order to help designers achieving a goal of greater sustainability. According to the listed heritage administration, dwelling types built before 1914 represent approximately 25 % of the Walloon stock. This project is related to the research work carried out under the Task 59 of SHC ‘Renovating Historic Buildings Towards Zero Energy’. The methodology used to achieve the research objectives is articulated in various steps. First, a typological analysis of buildings from the interest era is completed. Then, based on on-site studies performed on representative case studies, the evaluations of heritage values and performance are conducted. Finally, dynamic energy models are run to support the proposition and validation of retrofitting strategies

Combining multi-view photogrammetry and wireless sensor networks when modelling the hygrothermal behaviour of heritage buildings

The construction sector has now entered the 'Digital era', and professionals are slowly getting familiar with many of these innovative technologies. This paper shows how such innovations improve the investigation phase when it comes to energy retrofits on heritage buildings. More specifically, multi-view photogrammetry and wireless sensor networks can facilitate the implementation and enhance the relevance of building hygrothermal and energy simulations: photogrammetry quickens up the reproduction of the building geometry whereas wireless sensor networks facilitate and enlarge the collection of data relative to the existing behaviour of an occupied building. This paper explores the benefits of using those two technologies compared to more traditional solutions, regarding data quality and general workflow. In this purpose, two case studies from research projects ongoing in Belgium are briefly described

Heritage value combined with energy and sustainable retrofit: representative types of old Walloon dwellings built before 1914

Energy and sustainable retrofit of old buildings with heritage value is a challenging issue for Europe. The research project “P-RENEWAL” aims to develop a methodological tool for energy and sustainable retrofit of Walloon dwellings built before 1914, with heritage value. The present contribution will mainly discuss the methodology used to identify building typology and will also submit a detailed description of several building types. This methodology can be applied in other contexts to provide any user with data on different scales, from the building to the entire city, helping to make sustainable decisions

Combining multi-view photogrammetry and wireless sensor networks when modelling the hygrothermal behaviour of heritage buildings

The sustainable energy renovation of historical buildings is a challenge for all European countries. It is crucial for their conservation as well as for urban and rural development. Nonetheless, proposing adequate interventions requires appropriate investigation efforts. This paper presents a specific approach for performing the energy diagnosis of occupied historical buildings, developed under the contraints of several ongoing research projects. It is shown how photogrammetry and wireless sensor networks can be combined to produce rich datasets, while keeping disturbances for occupants at a minimum. Within this multi-disciplinary investigation program, the focus is also put on the production of input and validation data for implementing dynamic energy simulations. A case study is presented to illustrate the deployment of the proposed methodology. Only two site visits allowed to capture a large quantity of descriptive and performance information, which was valorized through clear protocols for sampling and formatting the data