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Recently, intensive technological development in the field of energy efficiency of buildings has occurred, which should enable the transition from nearly zero (nZEB), through net zero (NZEB) to ultimate zero energy buildings (ZEB). The last stage will also require a transition from the grid to onsite storage of each energy carrier needed for the operation of building technical systems (BTS). In the article, the method of optimization of energy storage is presented and demonstrated on the example of all-glass NZEB office buildings in different climates. The impact of energy storage was estimated by production matching fraction fpr,match and by the building autonomy factor (AUT). The metrics were determined by dynamic modelling of buildings with south-facing glazed BIPV facades. It was found that optimum energy storage capacities are in the range between 0.01 and 0.06 kWh/m2 for heat storage, 0.03 to 0.08 kWh/m2 for cold storage and 0.03 to 0.04 kWh/m2 for batteries per 1 m2 of useful area of the building. By integrating optimized energy storage in BTS, the fpr,match could be increased from 43% to 61% and AUT from 44% to 54%, indicating that energy storage significantly contributes to the transition of NZEB towards ZEB.

Since its introduction in 2010, the nearly Zero Energy Building (nZEB) concept has known a large diffusion in European countries. Albania, an aspiring candidate country to join the European Union EU, is paving the way towards its introduction by transposing EU directives in the fields of energy efficiency into the national legislation. Most of the national building stock includes buildings with low thermal and energy performance but with high refurbishment potential, too. The country can become an important contributor in the EU decarbonization strategy due to the high percentage of electricity produced by hydropower stations, making it one of the least carbon-intensity countries in the electricity production point of view. The article focuses on the evaluation of the energy performance of an existing school located in Tirana and the potentialities to reach the nZEB target, analysing both the suitable technological solutions and the energy market situation. The Primary Energy Factors PEF for the local electricity market are estimated referring to statistical data and in comparison, with neighbouring countries, Italy and Greece, in order to investigate the potential of the achievement of the nZEB target in Albania.

Aliniant-se amb l’ambiciós paquet energètic i climàtic de la UE 2030 per reduir les emissions d’efecte hivernacle i substituir les fonts de calor convencionals mitjançant la presència de participacions d’energia renovable per aconseguir una comunitat d’energia nul·la, les parts interessades del sector residencial s’enfronten a diversos aspectes tècnics, econòmics i ambientals. qüestions per assolir els objectius de la UE en un futur proper. Aquesta tesi se centra en dues transformacions estructurals claus necessàries per a una transició sostenible cap a la producció d’energia neta: el problema de les tecnologies d’energia amb baix carboni que representen els sistemes solars de calefacció urbana juntament amb l’emmagatzematge estacional d’energia i la seva aplicació per aconseguir edificis d’energia gairebé nul·la. L’abordatge d’aquests reptes s’inicia mitjançant l’ús del disseny i l’optimització de sistemes d’energia neta incorporats a l’aprenentatge automàtic i l’anàlisi de dades per desenvolupar eines d’enginyeria de processos assistits per ordinador. Aquestes eines ajudarien a abordar els reptes de les parts interessades, contribuint així a la transició cap a un futur més sostenible. Alineándose con el ambicioso paquete de energía y clima de la UE 2030 para reducir las emisiones de efecto invernadero y reemplazar las fuentes de calor convencionales a través de la presencia de energía renovable para lograr una comunidad de energía neta cero, las partes interesadas en el sector residencial se enfrentan a varios problemas técnicos, económicos y ambientales. cuestiones para cumplir los objetivos de la UE en un futuro próximo. Esta tesis se centra en dos transformaciones estructurales clave necesarias para la transición sostenible hacia la producción de energía limpia: el problema de las tecnologías energéticas bajas en carbono que representan los sistemas de calefacción de distrito solar junto con el almacenamiento de energía estacional, y su aplicación para lograr edificios de energía casi nula. El abordaje de estos desafíos se inicia mediante el uso del diseño y la optimización de sistemas de energía limpia incorporados con el aprendizaje automático y el análisis de datos para desarrollar herramientas de ingeniería de procesos asistida por computadora. Estas herramientas ayudarían a abordar los desafíos de las partes interesadas, contribuyendo así a la transición hacia un futuro más sostenible. Aligning with the ambitious EU 2030 climate and energy package for cutting the greenhouse emissions and replacing conventional heat sources through the presence of renewable energy share to achieve net-zero-energy community, the stakeholders at residential sector are facing several technical, economic, and environmental issues to meet the EU targets in the near future. This thesis is focusing on two key structural transformations needed for sustainable transition towards clean energy production: the low carbon energy technologies problem represented by the solar district heating systems coupled with seasonal energy storage, and its application to achieve Nearly Zero Energy Buildings. The Tackling for these challenges is instigated through using design and optimization of clean energy systems incorporated with machine learning and data analysis to develop Computer-Aided Process Engineering tools. These tools would help in addressing the stakeholder’s challenges, thus contributing to the transition towards a more sustainable future.

The Passive House standard has become the standard for many countries in the construction of the Zero Energy Building (ZEB). Korea also adopted the standard and has achieved great success in building energy savings. However, some issues remain with ZEBs in Korea. Among them, this study aims to discuss overheating issues. Field measurements were carried out to analyze the overheating risk for a library built as a ZEB. A data-driven overheating risk prediction model was developed to analyze the overheating risk, requiring only a small amount of data and extending the analysis throughout the year. The main factors causing overheating during both the cooling season and the intermediate seasons are also analyzed in detail. The overheating frequency exceeded 60% of days in July and August, the midsummer season in Korea. Overheating also occurred during the intermediate seasons when air conditioners were off, such as in May and October in Korea. Overheating during the cooling season was caused mainly by unexpected increases in occupancy rate, while overheating in the mid-term was mainly due to an increase in solar irradiation. This is because domestic ZEB standards define the reinforcement of insulation and airtight performance, but there are no standards for solar insolation through windows or for internal heat generation. The results of this study suggest that a fixed performance standard for ZEBs that does not reflect the climate or cultural characteristics of the region in which a ZEB is built may not result in energy savings at the operational stage and may not guarantee the thermal comfort of occupants.

Many uncertainties lie in the early design phase of a zero energy building which can affect the reliability of decision aid tools for ecodesign based on building performance simulation, life cycle analysis and multicriteria optimisation. This work starts with the identification of the main uncertainty sources in buildings LCA. A method for the quantification of influential uncertainties in buildings LCA is proposed with the aim to assess the robustness of a building design in a prospective context and with a limited computational cost. Then, this prospective dynamic LCA approach is integrated into the evaluation function of a genetic multicriteria optimisation algorithm in order to identify design solutions with environmental performances which are optimal and robust in the long term.; La présence de nombreuses incertitudes en phase de conception peut nuire à la fiabilité d’une aide à la décision pour l’écoconception de bâtiments zéro-énergie basée la simulation énergétique dynamique, l’analyse de cycle de vie et l’optimisation multicritère. Ces travaux de thèse débutent par l’identification des principales sources d’incertitudes en ACV des bâtiments. Puis, une méthode de quantification d’incertitudes significatives est proposée avec l’objectif d’évaluer la robustesse d’une variante de conception dans un contexte prospectif et pour un coût calculatoire limité. Enfin, cette approche d’ACV dynamique prospective est intégrée à la fonction d’évaluation d’un algorithme d’optimisation génétique multicritère afin d’identifier des solutions de conception aux performances environnementales optimales et robustes dans le temps.

Many uncertainties lie in the early design phase of a zero energy building which can affect the reliability of decision aid tools for ecodesign based on building performance simulation, life cycle analysis and multicriteria optimisation. This work starts with the identification of the main uncertainty sources in buildings LCA. A method for the quantification of influential uncertainties in buildings LCA is proposed with the aim to assess the robustness of a building design in a prospective context and with a limited computational cost. Then, this prospective dynamic LCA approach is integrated into the evaluation function of a genetic multicriteria optimisation algorithm in order to identify design solutions with environmental performances which are optimal and robust in the long term.; La présence de nombreuses incertitudes en phase de conception peut nuire à la fiabilité d’une aide à la décision pour l’écoconception de bâtiments zéro-énergie basée la simulation énergétique dynamique, l’analyse de cycle de vie et l’optimisation multicritère. Ces travaux de thèse débutent par l’identification des principales sources d’incertitudes en ACV des bâtiments. Puis, une méthode de quantification d’incertitudes significatives est proposée avec l’objectif d’évaluer la robustesse d’une variante de conception dans un contexte prospectif et pour un coût calculatoire limité. Enfin, cette approche d’ACV dynamique prospective est intégrée à la fonction d’évaluation d’un algorithme d’optimisation génétique multicritère afin d’identifier des solutions de conception aux performances environnementales optimales et robustes dans le temps.

The electrification of cooking methods in Korea was investigated to understand the impact of different cooking methods on energy use and greenhouse gas (GHG) emissions in the building sector. Annual household cooking energy consumption was compared for the Nowon Energy Zero House Project, a zero-energy housing complex using induction cooktops, and a sample of households that used natural gas for cooking. The results showed that the former consumed less calories (a difference of 2.2 times) and emitted less GHGs (a difference of 2.6 times) compared to gas cooking households. A countrywide scenario analysis was conducted by combining the share of electric cooking households with the projected power generation mix in 2030. Under the 2030 Policy scenario for power generation, and with an electricity cooking share of 20%, cooking-related GHG emissions were projected to be 3.79 million t CO2/year; 3.8% (150,000 t CO2/year) lower than those in the present day, despite a total population increase. The electrification of cooking methods in Korea has the potential to reduce both the energy demand of the building sector and GHG emissions, in synergy with the decarbonization of the power generation sector.

Regeneration of existing buildings and abandoned areas is a governmental and European key objective. This research focuses on Poveglia: an abandoned island in the Venetian lagoon, Italy. The underpinning idea concerns the upgrade of Poveglia to a zero energy Cognitive University Campus, connected to other educational institutions in the lagoon. The vision aims at reusing abandoned islands combining architecture, learning environments and digital networks, to demonstrate the potential of new technologies for the transformation of abandoned areas. The case study demonstrates the effectiveness of employing improved and revised systems and tools, developed in eLUX lab at the University of Brescia, for the regeneration of the island. The inclusion of the island in a smart campus network results in triggering positive synergies both enhancing energy efficiency and the learning environment. A further development concerns the setup of strategies for historical preservation, energy efficiency and renewable energy production.

The Indoor Environmental Quality (IEQ) is a basic requirement for the design of energy-efficient buildings since it affects the occupants’ well-being and health inside buildings. Over the years, the issue of IEQ has been widely investigated under different perspectives: from the first experiments aimed at assessing the physiological response of individuals it has become a human-centric concept. In recent years, new paradigms have influenced buildings design towards sustainable and highly efficient constructions. Zero-Energy Buildings (ZEBs) are the current challenge which should be appropriately addressed with a holistic approach to achieve excellent IEQ and energy efficiency levels. Thermal, visual and acoustic comfort and indoor air quality are the most important Indoor Environmental Factors (IEF) characterizing the overall environmental condition of indoor spaces. However, there is no standard method to calculate the overall IEQ level of a building by monitoring and aggregating all individual aspects of comfort. This article aims to bridge this gap, proposing a method to define weighting factors of IEFs. A survey was carried on 100 participants out in a fully monitored Zero-Energy full-scale test building to collect and analyse the answers of the sample about their evaluation of IEFs. The collected data of questionnaire-based IEQ responses were treated with a multiple linear regression model. The results prove that IEQ is affected mostly by IAQ during the test. The proposed weighting factors were applied to rank the monitoring-based IEFs. The comparison between objective (monitoring-based) and subjective (questionnaire-based) analyses shows how the former underestimates IEQ with respect to the latter.

Nell'ambito dell'Accordo Quadro di collaborazione tra Regione Lombardia e il Consiglio Nazionale delle Ricerche (CNR), il progetto I-ZEB "Verso Edifici Intelligenti a Energia Zero" ha portato alla realizzazione di un laboratorio ZEB in scala reale per analisi energetico-ambientali finalizzate alla valutazione delle prestazioni in condizioni reali di componenti di involucro ed impianto. Il laboratorio ZEB è il risultato di un intervento di riqualificazione di un edificio esistente che ha raggiunto i requisiti di Zero Energy Building in seguito al miglioramento delle prestazioni dei componenti di involucro e di impianto e all'integrazione con Fonti Energetiche Rinnovabili. Il sistema di monitoraggio installato consente l'acquisizione in continuo dei dati per la verifica e l'ottimizzazione delle prestazioni delle soluzioni installate, al fine di ridurre i consumi e migliorare la qualità dell'aria. La presente Relazione si riferisce unicamente ai prodotti caratterizzati, studiati ed ottimizzati così come ricevuti e installati nell'edificio sperimentale ZEB e non può essere riprodotta se non interamente. Nella Relazione pone un focus sugli interventi di riqualificazione energetica ed acustica dell'involucro opaco realizzati in collaborazione con il gruppo Rockwool. Nel Capitolo 2 viene descritto brevemente l'edificio ex ante dal punto di vista di inserimento nel contesto e geometrico, con un approfondimento nella descrizione dei componenti di involucro opachi. Dopo una descrizione sintetica di tutti gli interventi di riqualificazione eseguiti, nel Capitolo 3 si descrivono gli interventi di riqualificazione riferiti all'involucro opaco, dettagliando spessori e tipologia dei prodotti Rockwool applicati in base alla stratigrafia e alla prestazione iniziale. I due capitoli successivi sono dedicati alla descrizione delle verifiche energetiche ed acustiche eseguite. Il Capitolo 4 affronta le verifiche termografiche e di condensa interstiziale di specifiche soluzioni di involucro e infine analizza le prestazioni della facciata ventilata. Infine, il Capitolo 5 è dedicato alle verifiche delle prestazioni acustiche: dopo una descrizione del metodo, si descrivono le verifiche prestazionali della facciata ventilata, dell'isolamento a cappotto e della partizione interna.

Regeneration of existing buildings and abandoned areas is a governmental and European key objective. This research focuses on Poveglia: an abandoned island in the Venetian lagoon, Italy. The underpinning idea concerns the upgrade of Poveglia to a zero energy Cognitive University Campus, connected to other educational institutions in the lagoon. The vision aims at reusing abandoned islands combining architecture, learning environments and digital networks, to demonstrate the potential of new technologies for the transformation of abandoned areas. The case study demonstrates the effectiveness of employing improved and revised systems and tools, developed in eLUX lab at the University of Brescia, for the regeneration of the island. The inclusion of the island in a smart campus network results in triggering positive synergies both enhancing energy efficiency and the learning environment. A further development concerns the setup of strategies for historical preservation, energy efficiency and renewable energy production.

Zero Energy Buildings (ZEBs) are expected to play a significant role in reducing energy consumption and combating climate change. Despite this awareness, there is a lack of approaches and indicators at the regulatory level to quantify the long-term potential of strategies applied to buildings today. This study concerns the dynamic thermal modeling over the years, until 2080, of a multi-residential building located in Lecce, a city in southeastern Italy, characterized by a Mediterranean hot summer climate. Over time, Italian legislation has brought increasingly stringent limits on the design of the building envelope. Although with different regulatory limits, in the different climates across Italy, a growing trend towards a more insulated envelope, characterized by very low transmittances, has been observed over the years. This study shows how, in hot climates, buildings constructed within the legal limits will suffer from overheating over the years, necessarily leading to a disproportionate, and more extensive, use of cooling systems throughout the year. This study proposes a critical analysis of the long-term effectiveness of national strategies applied to the building envelope to date to achieve the ZEB goal, emphasizing that long-term predictive analyses become relevant in current building design and should be considered in regulations.

This study conducts a techno-economic analysis to seek the feasibility to integrate a zero-emission building (ZEB) with a commercial-scale hydrogen vehicle (HV). The parametric analysis is conducted in 16 simulation groups with respect to the equipment options of the solar thermal collectors, the ground source heat pump (GSHP) and the HV refueling methods, while each group contains a series of cases with a range of on-site renewable electricity (REe) generation capacities between 0 and 16 kW. The assessment criteria include the annual operational equivalent CO2 emission and the relative net present value (NPVrel). By the parametric analysis, the sets of the non-dominated cases within the cloud of the analysed solutions have been comprehensively investigated regarding the aims to reduce the emission and the cost. With respect to the criteria of the equivalent emission and NPVrel under the normal market scenario of the electrolyzer (5000 EUR/kW), none of the cases with the on-site H2 system can be identified as superior to those without the on-site H2 system. The non-dominated cases will mainly happen to those with a 0–9.61 NOCT kW photovoltaic (PV) panel and a 5 kW GSHP but without any solar thermal collector, which have a range of NPVrel between −4115 and 12,556 EUR along with a range of emission between 19.72 and 6.65 kg CO2,eq/m2 a. However, by reducing the electrolyzer cost to the lowest market scenario of 2000 EUR/kW, parts of the cases with the on-site H2 system start to challenge those without the on-site H2 system. Moreover, the change of the emission factor of the H2 fuel from 0.267 to 0.141 kg CO2,eq/kWhLHV will not alter the set of the overall non-dominated cases, but will uniformly reduce the annual emission of these cases by a magnitude of 3.83 kg CO2,eq/m2 a.

While a number of domains readily employ Unmanned Aerial Vehicles with infrared cameras (IR-UAVs), the IR and UAV research directions still need to be bridged in the construction domain. Our research aims to develop a protocol for IR-UAV flights to survey building thermography. Through a series of test flights and a literature study, the protocol was developed. The protocol was verified during a final test flight surveying PV-panels and the thermal shell of a building. By outlining the system, designing a protocol, and reflecting on our experiences, we contribute to the discussion to use IR-UAVs in the construction domain.

This thesis improves the scientific knowledge on the origin, behavior and fate of gas and particle-phase pollutants indoors under unoccupied unfurnished conditions. A first campaign provided a complete description of the physical processes controlling the indoor concentrations. Using well quantified parameters (air exchange rate, penetration factor and deposition rate), a mass balance model provided insights for the particle budget closure. The results showed that when indoor sources are not significant, a careful characterization of the abovementioned parameters allows to estimate PM2.5 and PM10 in a satisfying manner from outdoor data. However the PM1 fraction shows a significantly higher variability due to physicochemical transformations. Subsequently, a second intensive campaign was performed to investigate volatile organic compounds (VOC) and PM1 chemical composition in real time. A strong increase in VOC concentrations was observed when outdoor air penetrates indoors, especially oxygenated VOC which exhibited a significant dependence on relative humidity, while the changes observed for particles once indoors depend on their chemical composition and diameter, showing a decrease from 20% for submicron particles up to, 86% for large ones (>5. µm). The investigation of ammonium neutralization revealed an excess of ammonium indoors and outdoors, which is attributed to organic- in addition to inorganic-bonded ammonium nitrate. The latter showed a stronger dependency on temperature gradient from outdoors to indoors, revealing stronger thermal decomposition once indoors. In summary, the indoor environment acts mainly as a continuous emission source of VOCs, while the opposite trend is observed the particles due to possible transformations that can occur even under the simplest conditions, with no occupants and no furnishing.; Cette thèse développe les connaissances scientifiques sur l’origine et le comportement des polluants intérieurs en phases gazeuse et particulaire. Une description complète des processus physiques contrôlant les concentrations de polluants en air intérieur dans une pièce inoccupée et non meublée a été réalisée. En utilisant des paramètres bien quantifiés (taux de renouvellement d’air, facteur de pénétration et vitesse de dépôt), nous avons pu appliquer un modèle de bilan massique aux particules. Les résultats ont montré que, en l’absence significative de sources intérieures, une caractérisation fine des paramètres ci-dessus permettait de décrire de manière satisfaisante les concentrations intérieures en PM2.5 et PM10 à partir des données extérieures, tandis que les PM1 montrent une variabilité significativement plus marquée due aux transformations physicochimiques. Par la suite, les composés organiques volatils (COV) et la composition chimique des particules submicroniques ont été mesurés en temps réel lors d’une campagne intensive. Un enrichissement important des concentrations en COV a été observé lorsque l’air ambiant pénètre à l’intérieur du bâtiment, en particulier pour les COV oxygénés qui présentent une dépendance significative avec l’humidité relative, tandis que pour les particules les changements observés dépendent de leur composition chimique et de leur diamètre, montrant une diminution de 20% pour les PM1 à 86% pour les plus grosses particules (>5 μm). L’excès d’ammonium observé dans les deux environnements a permis de déconvoluer les nitrates organiques des inorganiques, ceux-ci présentant une dépendance plus forte avec la température, révélant une décomposition thermique plus importante en air intérieur. En résumé, l’environnement intérieur agit principalement comme une source d’émissions continues de COV, alors qu’une tendance inverse est observé pour les particules, du fait de transformations possibles pouvant se produire même dans les conditions les plus simples, sans occupant ni mobilier.

This thesis improves the scientific knowledge on the origin, behavior and fate of gas and particle-phase pollutants indoors under unoccupied unfurnished conditions. A first campaign provided a complete description of the physical processes controlling the indoor concentrations. Using well quantified parameters (air exchange rate, penetration factor and deposition rate), a mass balance model provided insights for the particle budget closure. The results showed that when indoor sources are not significant, a careful characterization of the abovementioned parameters allows to estimate PM2.5 and PM10 in a satisfying manner from outdoor data. However the PM1 fraction shows a significantly higher variability due to physicochemical transformations. Subsequently, a second intensive campaign was performed to investigate volatile organic compounds (VOC) and PM1 chemical composition in real time. A strong increase in VOC concentrations was observed when outdoor air penetrates indoors, especially oxygenated VOC which exhibited a significant dependence on relative humidity, while the changes observed for particles once indoors depend on their chemical composition and diameter, showing a decrease from 20% for submicron particles up to, 86% for large ones (>5. µm). The investigation of ammonium neutralization revealed an excess of ammonium indoors and outdoors, which is attributed to organic- in addition to inorganic-bonded ammonium nitrate. The latter showed a stronger dependency on temperature gradient from outdoors to indoors, revealing stronger thermal decomposition once indoors. In summary, the indoor environment acts mainly as a continuous emission source of VOCs, while the opposite trend is observed the particles due to possible transformations that can occur even under the simplest conditions, with no occupants and no furnishing.; Cette thèse développe les connaissances scientifiques sur l’origine et le comportement des polluants intérieurs en phases gazeuse et particulaire. Une description complète des processus physiques contrôlant les concentrations de polluants en air intérieur dans une pièce inoccupée et non meublée a été réalisée. En utilisant des paramètres bien quantifiés (taux de renouvellement d’air, facteur de pénétration et vitesse de dépôt), nous avons pu appliquer un modèle de bilan massique aux particules. Les résultats ont montré que, en l’absence significative de sources intérieures, une caractérisation fine des paramètres ci-dessus permettait de décrire de manière satisfaisante les concentrations intérieures en PM2.5 et PM10 à partir des données extérieures, tandis que les PM1 montrent une variabilité significativement plus marquée due aux transformations physicochimiques. Par la suite, les composés organiques volatils (COV) et la composition chimique des particules submicroniques ont été mesurés en temps réel lors d’une campagne intensive. Un enrichissement important des concentrations en COV a été observé lorsque l’air ambiant pénètre à l’intérieur du bâtiment, en particulier pour les COV oxygénés qui présentent une dépendance significative avec l’humidité relative, tandis que pour les particules les changements observés dépendent de leur composition chimique et de leur diamètre, montrant une diminution de 20% pour les PM1 à 86% pour les plus grosses particules (>5 μm). L’excès d’ammonium observé dans les deux environnements a permis de déconvoluer les nitrates organiques des inorganiques, ceux-ci présentant une dépendance plus forte avec la température, révélant une décomposition thermique plus importante en air intérieur. En résumé, l’environnement intérieur agit principalement comme une source d’émissions continues de COV, alors qu’une tendance inverse est observé pour les particules, du fait de transformations possibles pouvant se produire même dans les conditions les plus simples, sans occupant ni mobilier.

There is much research on zero energy buildings. In this paper, technologies and policies to improve the building energy efficiency of zero energy buildings are presented. The zero energy building certification system in Korea is introduced, and the evaluation is carried out based on the energy self-reliance rate that enables zero energy buildings. Zero energy buildings are able to minimize energy consumption due to the application of highly efficient building materials and equipment technology. In this research, to increase the prevalence of zero energy buildings in Korea, the authors propose a zero energy building technology package. Using a passive and active technology package, we confirmed the necessity and detailed requirements of each technology parameter. We analyze and classify Korean building material testing methods and performance standards, and propose passive and active technology packages, modules, material performance testing methods and minimum requirement performance standards. Finally, this study proposed a table presenting the test methods, standard and minimum value of performance. By these results, the authors confirmed the effectiveness and availability of passive and active technical packages.

The international scientific community believes unequivocally that, at the origin of the climate change, there are anthropic factors mainly linked to the construction sector and to the disproportionate use of fossil energy sources. The selection of building materials plays a key role in the reduction of energy consumption, especially in the Mediterranean area, where the internal overeating risk is high if the solar radiation is not controlled and the free supply of internal heat is poorly managed. Traditionally, in the Italian context, the slab-on-ground floor is made in concrete or more rarely in stone. However, it is usually recommended to minimize the use of concrete as it has a strong environmental impact, reinforced concrete is still the most recommended solution for foundations, both for regulatory and practical reasons. The present study proposes a methodology for the design of high efficiency slab-on-ground floor for warm climate through optimization code performed with the software modeFRONTIER. Starting from the traditional floor structures, the multi-objective methodology stands as an advanced step for the identification of new configurations, favoring the management of many variables, such as thermal, environmental and economic aspects. The results are characterized by high presence of local and eco-friendly materials and reduced costs. At the end, this work demonstrates that it is possible to obtain high performance solutions with also very few numbers of layers.

The enhancement of energy performance of buildings has become a pillar of energy policies. The main target is the cut of energy consumption to reduce buildings footprint. This aim is pursued by introducing constrains on building requirements in terms of properties of basic materials and components and exploitation of renewable energy sources . That results in the definition of the zero-energy building (ZEB) concept. The new paradigm introduced new challenges and, at the same time, involved all the different stakeholders in facing the barriers to the diffusion of the novel solutions proposed by the research development. This paper summarizes the actual state-of-art of whole performance of ZEBs and the related technical solutions, analysing their increasing potential in energy consumption. A collection of the different case studies reported in literature involving ZEBs is presented, compiling an analysis of the performance of the common solutions actually applied. The technologies involved are described discussing their impact in meeting the ZEB requirements. A debate is proposed, pointing out the main aspects deserving further investigations and outlining the critical elements in making the zero-energy target the new standard for the buildings.