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Among environmental controls, solar shading and ventilative cooling are widely considered as key passive strategies for limiting the overheating risks in buildings. While their application is encouraged through Energy Performance of Buildings Directive regulations, several studies have shown that summer thermal comfort in heating-dominate temperate climates still requires deeper investigation, particularly in low-energy residential buildings. Based on qualitative and quantitative data collected through surveys and monitoring in 147 highly insulated houses in Wallonia (Belgium), this paper gives an overview of the implemented passive strategies and discusses their effectiveness. Statistical tests are conducted to evaluate their impact on both perceived and measured indoor conditions. In general, the results highlight a limited impact of the implemented strategies, questioning their proper operation. Operational modes for environmental controls thus appear crucial, and should better respond to occupants’ needs, preferences and control opportunities. At a more general level, the study calls for a better understanding of the barriers inhibiting successful integration and operation of environmental controls, in order to effectively reduce overheating risks in residential buildings and limit future diffusion of active cooling systems with their induced environmental impacts., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care. Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Real Estate Management

While the potential impact of climate change mitigation measures is well documented in building sciences literature, there are only relatively sparse studies focusing on the efficiency of adaptation strategies. This paper aims to contribute to this topic by evaluating the extent to which the design of a typical nearly Zero Energy Buildling (nZEB) house in Wallonia (Belgium), and its current operation, could provide summer thermal comfort in a changing climate. Based on calibrated whole building energy simulations, and on the integration of future climate data directly derived from a high-resolution climate model, this study evaluates the potential evolution of overheating risks in the living room and in the main bedroom of the house. Discussing the compliance with existing overheating criteria, the study shows that the passive strategies currently deployed in the house might not be sufficient to guarantee summer thermal comfort especially in the bedroom, and that other strategies might be necessary in the future to limit the use of active cooling systems and curb their environmental impacts. This study concludes that considering the potential of these strategies to guarantee summer thermal comfort in a changing climate should be a priority for the design of nZEB houses (and their related policies) also in temperate oceanic climates., Real Estate Management

While the potential impact of climate change mitigation measures is well documented in building sciences literature, there are only relatively sparse studies focusing on the efficiency of adaptation strategies. This paper aims to contribute to this topic by evaluating the extent to which the design of a typical nearly Zero Energy Buildling (nZEB) house in Wallonia (Belgium), and its current operation, could provide summer thermal comfort in a changing climate. Based on calibrated whole building energy simulations, and on the integration of future climate data directly derived from a high-resolution climate model, this study evaluates the potential evolution of overheating risks in the living room and in the main bedroom of the house. Discussing the compliance with existing overheating criteria, the study shows that the passive strategies currently deployed in the house might not be sufficient to guarantee summer thermal comfort especially in the bedroom, and that other strategies might be necessary in the future to limit the use of active cooling systems and curb their environmental impacts. This study concludes that considering the potential of these strategies to guarantee summer thermal comfort in a changing climate should be a priority for the design of nZEB houses (and their related policies) also in temperate oceanic climates.

Les périodes de vagues de chaleur vont s’intensifier et devenir de plus en plus fréquentes. Face à l'évolution du climat annoncée, et sans évolution du bâti existant, il sera de plus en plus difficile de garantir un confort thermique estival acceptable à l'intérieur des logements, y compris en climat tempéré. L'efficacité des solutions de protections solaires et de ventilation intensive n'est plus à démontrer. Elles constituent une alternative à la climatisation ou au minimum, un moyen d’en limiter les consommations énergétiques et l’impact environnemental. Cependant, elles ne semblent, en Wallonie, que peu implémentées en pratique dans le secteur résidentiel. Par ailleurs, leur gestion par les occupants, souvent manuelle, semble souvent inadaptée ou insuffisante alors que des solutions techniques intelligentes (prédiction, auto-apprentissage, intelligence artificielle, etc.) ouvrent la voie vers de nouvelles possibilités. Dans ce contexte, le projet SOFTSummer (pour Smart Operation For Thermal SUMMER comfort in residential buildings) vise un double objectif. Il vise, d’une part, à identifier le potentiel des solutions de gestion des protections solaires et de ventilation intensive pour garantir le confort thermique d’été dans les bâtiments résidentiels. Cela implique d’évaluer à la fois le potentiel de développement technologique des systèmes de gestion et, leur impact potentiel sur le confort thermique estival dans les bâtiments résidentiels. D’autre part, le projet vise à identifier les freins et leviers à l’implémentation effective et inclusive de ces techniques par les différents acteurs intervenant dans le processus de construction (architecte, entrepreneurs, occupants, etc.). Atteindre ces objectifs nécessite un travail basé sur des approches croisées et interdisciplinaires aux frontières de l’ingénierie et de la sociologie appliquées à des domaines comme la construction, les technologies de l’information (TIC), la physique du bâtiment et l’habitat. En conséq

In a context of global warming, summer thermal comfort is a key issue for the design and operation of nearly zero-energy buildings (nZEBs). Although there are various methods and benchmarks for the long-term evaluation of summer thermal conditions in free-running buildings, their application to the residential sector is still debated. Based on data from post-occupancy measurements and survey campaigns, this paper evaluates the compliance with commonly used overheating criteria defined by existing standards (CIBSE and Passive House Institute) of 23 nZEB houses in Wallonia (Belgium). The quantitative relationship between measured and perceived comfort is statistically analysed, and building characteristics leading to the most critical overheating situations are qualitatively discussed. The results show that summer thermal discomfort is frequent in nZEB houses in Wallonia, despite its temperate climate. In living rooms, the long-term appraisal of thermal conditions appears to be related to the frequency of extreme temperatures, while occupants’ thermal perception in bedrooms seems to be more affected by smaller temperature deviations. These results imply a critical review of the capacity of the criteria commonly used for the evaluation of overheating risks in free-running residential buildings to predict the satisfaction of occupants with their summer thermal comfort. More generally, the findings reinforce the importance of a better integration, even in temperate climates, of environmental controls – and their required operation by the occupants – to properly mitigate overheating risks in nZEB houses., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Housing Management

In a context of global warming, summer thermal comfort is a key issue for the design and operation of nearly zero-energy buildings (nZEBs). Although there are various methods and benchmarks for the long-term evaluation of summer thermal conditions in free-running buildings, their application to the residential sector is still debated. Based on data from post-occupancy measurements and survey campaigns, this paper evaluates the compliance with commonly used overheating criteria defined by existing standards (CIBSE and Passive House Institute) of 23 nZEB houses in Wallonia (Belgium). The quantitative relationship between measured and perceived comfort is statistically analysed, and building characteristics leading to the most critical overheating situations are qualitatively discussed. The results show that summer thermal discomfort is frequent in nZEB houses in Wallonia, despite its temperate climate. In living rooms, the long-term appraisal of thermal conditions appears to be related to the frequency of extreme temperatures, while occupants’ thermal perception in bedrooms seems to be more affected by smaller temperature deviations. These results imply a critical review of the capacity of the criteria commonly used for the evaluation of overheating risks in free-running residential buildings to predict the satisfaction of occupants with their summer thermal comfort. More generally, the findings reinforce the importance of a better integration, even in temperate climates, of environmental controls – and their required operation by the occupants – to properly mitigate overheating risks in nZEB houses.

Today, facing climate change represents a double challenge for the building sector. On one hand, the sector has to reduce its impact in terms of greenhouse gas emissions and on the other hand designers have to guarantee comfortable indoor climate conditions in a changing climate. In this context, Wallonia (southern part of Belgium) is engaged in a drastic reduction of its greenhouse gas emissions and aims to reach a Carbon Neutral building stock by 2050. This relies on the generalization of the nearly Zero Energy Buildings (nZEB) concept for all buildings, including existing ones. In temperate oceanic climate, it mainly implies a drastic reduction of buildings heating energy demand by high thermal insulation levels and airtightness of the building envelope. Many studies have however shown that indoor summer thermal comfort in nZEB requires specific attention even in current climate. It is also clear that global warming will have a worsening impact on overheating risks in buildings. The aim of this paper is to evaluate the evolution of overheating risk of a typical nZEB house in Wallonia, in the frame of the changing climate. A whole building energy simulation of the house has been carried out using TRNsys18 simulation engine. The model has first been calibrated based on previous measurements, using ASHRAE guideline 14 indicators, in order to realistically evaluate the indoor summer thermal conditions encountered in the house. Data for current and future climatic conditions have been directly derived from high-resolution climate model. These models, dynamically downscaled from Global Climate Models (GCM), consider local climate variations and anomalies and allow a detailed geographical resolution (horizontal grid spacing <4km). Today, they are available in Belgium within the CORDEX project for the different representative concentration pathways (RCP). On these bases, the paper discusses the potential evolution of overheating risks in the living room and in the main b

Ce rapport reprend les résultats de l’étude MEASURE (MEsures de performAnces réelles et de Satisfaction des occUpants dans les bâtiments Résidentiels à hautes performances Energétiques) concernant le climat intérieur. Cette étude a été menée conjointement par Architecture et Climat et le Centre Scientifique et Technique de la Construction (CSTC) grâce à un financement de la Wallonie (DG04). Elle objective rigoureusement la perception du confort dans les logements basse énergie et passifs, sur base de mesures de plusieurs mois, d’enquêtes par questionnaires et d’interviews.

The main objective of the BTP1000 project was to design (and build) an office building (€coffice) that would comply to the PassivHauss principles, offer a very high comfort and integrate different sustainability features, but cost no more than a traditional building. In order to achieve those objectives, an integrated iterative design approach was followed. From the beginning of the project, all stakeholders and various building specialists contributed to the decision making process, and design alternatives where evaluated from various perspectives (e.g. energy performance, comfort, life cycle cost and impact,…). The present paper focuses on how life cycle analysis (LCA) and life cycle costing (LCC) were used to integrate environmental and economic dimensions in the design process of the building envelope and how the results influenced final design options. LCA and LCC studies first compared different types of façades. The best compromise between LCC and LCA results, practical implementation, and thermal comfort were then selected for implementation. Subsequently, parametric energetic simulation results (combining heating, cooling, lighting, and ventilation) were used as input for LCA and LCC studies in order to optimise the insulation level of the building fabric elements (outer walls, roof, ground floor, glazing). In conclusion, LCC and LCA were very useful in the integrated design process and results showed the importance of taking into account not only the energy use for heating and cooling, but also for lighting into the building fabric optimisation., The main objective of the BTP1000 project was to design (and build) an office building (€coffice) that would comply to the PassivHauss principles, offer a very high comfort and integrate different sustainability features, but cost no more than a traditional building. In order to achieve those objectives, an integrated iterative design approach was followed. From the beginning of the project, all stakeholders and various building specialists contributed to the decision making process, and design alternatives where evaluated from various perspectives (e.g. energy performance, comfort, life cycle cost and impact,…). The present paper focuses on how life cycle analysis (LCA) and life cycle costing (LCC) were used to integrate environmental and economic dimensions in the design process of the building envelope and how the results influenced final design options. LCA and LCC studies first compared different types of façades. The best compromise between LCC and LCA results, practical implementation, and thermal comfort were then selected for implementation. Subsequently, parametric energetic simulation results (combining heating, cooling, lighting, and ventilation) were used as input for LCA and LCC studies in order to optimise the insulation level of the building fabric elements (outer walls, roof, ground floor, glazing). In conclusion, LCC and LCA were very useful in the integrated design process and results showed the importance of taking into account not only the energy use for heating and cooling, but also for lighting into the building fabric optimisation.

In Europe, energy requirements are even stronger leading the construction sector to design buildings whose energy consumption is continuously reduced. Mainly, the global challenge today is to identify lacks in construction processes and misuse or misunderstanding on the side of the occupants in order to improve the design of efficient and comfortable high energy performance buildings. This paper presents the results of a large post occupancy evaluation (POE) by means of a survey questionnaire conducted on a sample of 458 Walloon high performances houses built within the frame of the action “Construire Avec l’Energie” (CALE). The results of the POE allow to qualify and discuss: the satisfaction regarding thermal and respiratory comfort; the occupants’ behaviour and satisfaction in relation to the use of the building and its systems; the actual consumptions compared with the predicted ones.

ENERGIE+ is a free decision-making guide available online and helping to check and to act on the energy consumptions and costs of building(s) in tertiary sector. It is mainly intended for the Energy Managers but also for architects, designers, installers or anyone in charge of energy in non-residential buildings, with a focus on renovation, construction, managing and raising awareness in projects aiming at energy efficiency. The structure of the information about energy, comfort, building and HVAC techniques and components is split into two parts. The first part, called The Decision-Making, is more practical and gives critical analyses and advices according to the project’s phase: Manage, Evaluate, Improve and Design. The second part is more theoretical and is called The Resources. It describes the systems and the components of a building, presents physical building theories, provides calculation tools, explains the different European and Belgian regulations, shows the measurement techniques and develops some case studies and relevant technical and physical values. This paper presents the purposes, the structure and the impact of the almost 800 times daily-visited online free ENERGIE+ guide which is a project of energy efficiency promotion and aims at the transfer of a large range of scientific and technical knowledge directly to the person in charge of the energy management in a public or private institution.

In Europe, since the application of the European Energy Performance of Buildings Directive (EPBD), energy requirements have been ever stronger, leading the construction industry to design buildings whose energy consumption is continuously reduced. Nevertheless, no large-scale experience feedbacks on the occupants’ satisfaction of high efficient residential buildings are available in Wallonia. Therefore, the first MEASURE project objective is the evaluation of occupants’ satisfaction in high energy performance dwellings by the use of a questionnaire. This questionnaire, divided in several parts, covers a technical description of the building and its systems, a global appreciation of the building in terms of respiratory, thermal, acoustic and luminous comfort and a detailed evaluation of the occupants’ satisfaction. The responses should permit to identify attention points and improvements required to achieve a comfortable environment for occupants and increase the effectiveness of energy performance. This paper focuses on the methodological approach used to establish a questionnaire adapted to the evaluation of the occupants’ satisfaction in high energy performance dwellings. It describes the different stages of the questionnaire realisation: the identification of dependent and independent notions to study as well as indicators defining each notion, the focus-group step and the test of the

Since these last years, the application of the European Energy Performance Building Directive (EPBD) has led to a higher interest in summer comfort issue. In this context, the design of glazing complexes (glazing and solar shading) is a key issue since it directly influences the thermal and visual perception of interior spaces. Glazing complex determine the view and the opening to the outside, determining solar gains and penetration of natural light, but is also responsible for heat loss and can cause overheating and glare. The choice of an adequate glazing complex should therefore be done considering all of these aspects. This paper presents a free web tool realised within the frame of the PROSOLIS research project. Based on a set of results obtained by the advanced use of BSDF functions for optical properties description of solar shading in specific thermal and daylight simulation software’s (WINDOW 7, EnergyPlus 8, Light-tools 8.0), the PROSOLIS web tool helps to evaluate the impact of the glazing complex choice on both thermal and visual comforts in residential and office buildings. This web tool, dedicated to building designers, proposes a multi-criteria approach for comparing accurately the most current types of glazing complexes. It considers internal and external screen fabrics and venetian blinds, combined with five different types of glazing and informs designers on energy and light performance levels of the selected combinations. From this information, designer should be able to easily choose glazing complexes fitting with their needs.

Mise à jour de la partie Climatisation du site Energie+ (aide à la décision en efficacité énergétique des bâtiments). Accessible sur : energieplus-lesite.be

The evaluation of cooling needs and summer comfort in buildings requires an accurate quantification of solar gains through window systems (glazing and solar shading). However, in dynamic thermal simulation tools, the modelling of shading devices is usually simplified: angular dependency of properties is neglected; shading devices are considered as perfect diffuser; internal reflections between the slats of a venetian blind are neglected or considered only as diffuse. In some cases these simplifications bring significant inaccuracies on the evaluation of solar gains entering the building, and, consequently, on the building thermal behaviour. Bi-directional Scattering Distribution Functions (BSDF) allows a more detailed modelling of materials and systems which enhances the characterisation of the window behavior. The use of these functions appears to be an appropriate way to consider optical angular properties of shading devices in dynamic thermal simulations: it increases the accuracy of results without requiring excessive computation time. This paper shows and discusses the results obtained when using-directional Scattering Distribution Functions in dynamic thermal simulation, for six common configurations of solar shading devices (external screen and venetian blinds of different characteristics), in comparison with those obtained by simplified modelling methods. The Window 7 software was used to generate BSDF data that were then used as input in the EnergyPlus V8 building energy simulation program. Results focus on transmitted solar energy through windows (double low E glazing) and cooling needs of a simple office room for the different solar shading devices. In conclusion, this study shows for several solar shading types (and their characteristics), the importance of considering optical angular properties in dynamic thermal simulation and the accuracy gained obtained by BSDF characterisation.

Mise à jour de la partie Eclairage du site Energie+ (aide à la décision en efficacité énergétique des bâtiments). Accessible sur: wwww.energieplus-lesite.be

La notion de NZEB, en tant qu’indicateur de performance, doit répondre à un triple objectif de rigueur scientifique, d'ambition proportionnelle à l'enjeu et de pragmatisme. Nous montrons que la définition actuelle des NZEB ne répond pas de façon optimale à ces 3 exigences. Dès lors, nous proposons une autre approche de la performance énergétique des bâtiments, centrée sur la dissociation des indicateurs et leur évaluation relative aux potentiels et contraintes du projet d’architecture. Plus qu’une redéfinition, le résultat de cet article est l’embryon d’un outil de guidance énergétique parallèle aux étapes de développement d'un projet.

Mise à jour de la partie relative à l'isolation thermique de l'enveloppe des bâtiments tertiaires http://www.energieplus-lesite.be

This study intends to compare different HVAC solutions for the “€COFFICE” office building designed according to the PassivHaus principles. Dynamic simulations of 4 families of HVAC solutions are conducted: traditional active heating and cooling supplied through water networks; heating and cooling supply based on the mechanical ventilation network; geothermal heat pumps; natural or mechanical night-cooling strategies combined with active heating and cooling assistance. Results indicate that geothermal solutions are the most efficient ones for the €COFFICE building. Second best are the night-cooling strategies, including mechanical ones. Heating and cooling supply through the mechanical ventilation network present a large variation of performances according to design and control parameters.

Pour mener à bien un projet de construction et de rénovation, il faut tout d’abord analyser la situation existante : - Quel est le confort fourni ? - Que consomme l’installation par rapport à une installation performante ? - Quelle est l’effic acité énergétique des équipements, … ? - Que peut rapporter une rénovation ? Ensuite, il s’agit de réaliser une nouvelle installation performante : - Quels sont les équipements existants sur le marché ? - Peut-on remplacer simplement certains équipements ou faut-il remplacer toute l’installation ? - Comment éclairer un local équipé d'ordinateurs, une salle de classe ou une chambre d’hôpital ? - Comment climatiser une salle de conférence ? - Quelle chaudière choisir ? - Quelles techniques de cuisson choisir en cuisines collectives ? - Comment rénover la toiture ? - Combien de luminaires faut-il installer ? - Comment les disposer? C’est à toutes ces questions que répond la version 6 du site internet Énergie+ :http://www.energieplus-lesite.be

Pour répondre à la demande régionale de définir des critères de performance énergétique passive appliquée aux spécificités des bâtiments tertiaires, l'étude a examiné (Partie 1) les spécificités des critères passifs appliqués aux bâtiments tertiaires ;(Partie 2) a comparé un ensemble de méthodes et de bâtiments de référence ;(Partie 3) a développé une approche paramétrique (PEB et PHPP) ;(Partie 4) a organisé une table ronde permettant aux acteurs (professionnels, administrations, etc.) de créer des consensus autour de valeurs retenues. En conclusion (Partie 5), des modalités de calcul/vérification sont proposées à la Région pour alimenter sa réflexion réglementaire., IBGE E06-166, info:eu-repo/semantics/nonPublished