Visual integration of the building interior and exterior is one of the charms of today's architecture. The Double-Skin facade system is a technology that can reduce the drawbacks of using glass in a building's elevation. In fact, the double-skin façade (DSF) offers transparency while reducing energy consumption when compared to single-skin systems in cold and moderate weather conditions. However, there is no clear evidence of how the system will perform in hot climate conditions. In this research, a testing procedure was established to experimentally evaluate the performance of the double-skin façade system, data was collected to create multiple regression models, and then evaluate the double-skin façade's performance and compare it to a single-skin system in hot arid climate conditions. / Doctor of Philosophy / Improving the quality of indoor environments is a main goal in today’s architecture. Towards this goal, the use of glass and curtain walls is common in office buildings. The building façade is a key factor for the amount of energy consumed to reach comfort levels in the building. That is, because facades influence lighting, glare, heat gain, noise safety and energy usage. Therefore, the use of glass improves transparency which can interfere with comfort levels inside the building due to solar heat gain. The Double Skin façade system is widely adopted in Europe and has been shown to reduce energy used for heating in cold weather. In winter, heat losses can be reduced as the system’s intermediate cavity acts as a thermal buffer. However, there is no clear understanding of how the system will perform in hot arid climate conditions where cooling is the dominant operating mode. A Double Skin Façade can provide shading during the overheating period, while having the desired glass elevations sought by designers. This is due to ventilation and solar control devices located inside the system’s cavity. Being placed between the interior and the exterior glass panels, solar control devices are protected from the weather, which in return decreases its size. Furthermore, the additional glass panel allows windows in the system’s inner layer to be opened for natural ventilation. Unfortunately, the performance of the Double Skin Façade system for hot arid climate is not well documented. Therefore, the primary goal of this research is to compare the thermal and light performance of the Double Skin Façade system to a single façade system for hot weather conditions.

On souhaite détecter puis modéliser les façades de bâtiments à partir des données acquises par le véhicule de numérisation mobile de l'ign, le Stéréopolis. Il s'agit de trouver une représentation géométrique des façades adapté aux données (signal lidar/laser et images optiques).La méthode doit être automatique et rendre possible la modélisation d'un grand nombre de façades afin de contribuer à la production de maquettes numériques de villes. Les verrous techniques proviennent de l'acquisition mobile en environnement urbain non contrôlé (géo référencement du véhicule, densité variable de points lidar...), ils proviennent du signal lidar, issu d'une technologie relativement récente et pour lequel le processus de traitement n'est pas encore consensuel : faut-il exploiter ou non la géométrie capteur ? Enfin, la quantité de données pose le problème du passage à l'échelle. Afin d'analyser la géométrie des nuages de points 3D lidar, nous avons proposé des attributs décrivant pour chaque point la forme de l'environnement local (linéaire-1D, planaire-2D ou volumique-3D).Les plans principaux des façades sont extraits automatiquement des données lidar grâce à un algorithme streamé de détection de rectangles verticaux. Nous avons développé deux modèles qui sont initialisés par ces rectangles. Une grille irrégulière dont chaque case, parallèle au plan principal peut avancer ou reculer. Une grille déformable qui est ''poussée par les rayons lasers jusqu’aux points lasers’ ‘Enfin, nous avons montré comment la grille déformable peut être rendue cohérente avec les images optiques en alignant les discontinuités géométriques de la grille avec des discontinuités radiométriques des images / One wishes to detect and model building façades from data acquired by the ign mobile scanning vehicle, the Stereopolis. It is a question of finding a geometric representation of facades appropriate to the data (lidar/laser signal and optical images).The method should be automatic and enable the modeling of a large number of facade to help the production of digital city models. Technical obstacles come from the mobile acquisition in uncontrolled urban environment (vehicle georeferencing, variable lidar point density...), they come from the lidar signal, retrieved from a relatively new technology for which the process is not yet consensus :does one operates into sensor geometry or not ? Finally, the amount of data raises the problem of scaling up. To analyze the geometry of lidar 3D point clouds, we proposed attributes describing for each point the shape of the local surroundings (linear-1D, planar-2D or volume-3D).The facade main planes are automatically extracted from lidar data through a streamed detection algorithm of vertical rectangles. We developed two models that are initialized by these rectangles. An irregular grid in which each cell, parallel to the main plane can move forward or backward. A deformable grid which is ''pushed by the laser beams toward the laser points''. Finally, we showed how the deformable grid can be made consistent with the optical images aligning the geometric discontinuities of the grid with radiometric discontinuities of the images

The main objectives of this research are (a) to investigate the thermal effect of double skin facades in office buildings in hot climates and (b) to propose guidelines for their efficient design based on this evaluation. The study involves the energy performance analysis of two buildings in India. A base case with the existing building skin was simulated for both the cities. The main source for the high cooling loads was found to be heat gain through windows and walls. This led to the evolution of a series of facade strategies with the goals of reducing heat gain, providing ventilation and day-lighting. The buildings were then simulated for their energy performance with the proposed double-skin strategies. Each of these strategies was varied according to the layers constituting the facade, the transparency of the facade and the orientation of the facade to which it is applied. Final comparisons of energy consumption were made between the proposed options and the base case to find the most efficient strategy and also the factors that affected this efficiency. The simulations were done using the building simulation software, Ener-Win. The double skin was simulated as per an approximate and simplistic calculation of the u-value, solar heat gain coefficient and transmissivity properties of the layers constituting the facade. The model relied on logically arrived at assumptions about the facade properties that were approximately within 10% range of measured values. Based on inferences drawn from these simulations, a set of design guidelines comprised of goals and parameters was generated for design of double-skin facades in hot climates typical to most of the Indian subcontinent. It was realized that the double-skin defined typically as a 'pair of glass skins separated by an air corridor' may not be an entirely energy efficient design strategy for hot climates. However, when used appropriately in combination with other materials, in the right orientation and with the right transparency, a double-layered facade turns out to be an energy efficient solution.

Much of the existing commercial building stock is aging and will be in need of upgrades now or within the next twenty years. Typically, enclosure retrofits consist of adding insulation to the exterior or interior of the existing façade. In this thesis, an alternative solution is examined, whereby a glass façade is added to the exterior of the existing building, forming a double façade. For historic buildings, this could preserve and protect the existing façade without completely covering it up. For outdated buildings, this could modernize the existing façade, giving it the all-glazed appearance that is currently so popular among architects. Regardless of the retrofit motive, it is important to be able to quantitatively compare retrofit solutions to make informed design decisions. As such, building simulation can be an important design tool. At present, there is no available simulation tool that can easily and accurately model a double façade; therefore, a double façade (DoFa) model was developed to fill this gap. A spreadsheet-based, lumped model was created and validated using current complex fenestration models and limited experimental data. Further experimental data is required to validate all aspects of the model. Results showed that the DoFa model can achieve accurate results; however, further development is needed to predict optical properties of venetian blinds and convective coefficients for natural airflow in double façade cavities. The model was used to compare double façades to traditional glazing systems. Results indicated that double façades can perform comparably to double glazing with outdoor shading in summer, and triple glazing in winter. However, the results are only valid for the tested glazing systems. In a second application, the DoFa model was modified to simulate an entire enclosure to compare a double façade retrofit to more traditional retrofit strategies. Results suggested that a double façade provides a good improvement in winter performance, though summer overheating is a concern. For the case study examined, a double façade would have performed better than the chosen retrofit of replacing the windows with double glazing and indoor shading, without insulating the opaque components. The DoFa model can be very useful in creating double façade preliminary design and operation strategies. At present, the DoFa model is an instantaneous, stand-alone tool. Further development is needed to pair the DoFa model with whole building energy simulations.

The main objectives of this research are (a) to investigate the thermal effect of double skin facades in office buildings in hot climates and (b) to propose guidelines for their efficient design based on this evaluation. The study involves the energy performance analysis of two buildings in India. A base case with the existing building skin was simulated for both the cities. The main source for the high cooling loads was found to be heat gain through windows and walls. This led to the evolution of a series of facade strategies with the goals of reducing heat gain, providing ventilation and day-lighting. The buildings were then simulated for their energy performance with the proposed double-skin strategies. Each of these strategies was varied according to the layers constituting the facade, the transparency of the facade and the orientation of the facade to which it is applied. Final comparisons of energy consumption were made between the proposed options and the base case to find the most efficient strategy and also the factors that affected this efficiency. The simulations were done using the building simulation software, Ener-Win. The double skin was simulated as per an approximate and simplistic calculation of the u-value, solar heat gain coefficient and transmissivity properties of the layers constituting the facade. The model relied on logically arrived at assumptions about the facade properties that were approximately within 10% range of measured values. Based on inferences drawn from these simulations, a set of design guidelines comprised of goals and parameters was generated for design of double-skin facades in hot climates typical to most of the Indian subcontinent. It was realized that the double-skin defined typically as a 'pair of glass skins separated by an air corridor' may not be an entirely energy efficient design strategy for hot climates. However, when used appropriately in combination with other materials, in the right orientation and with the right transparency, a double-layered facade turns out to be an energy efficient solution.

Akivaizdu, kad dėl didelės apdailos medžiagų bei pastatų funkcinės ir architektūrinės paskirties įvairovės, sunku pasirinkti geriausią fasado apdailą. Todėl baigiamojo magistro darbo tikslas yra apdailos medžiagų variantų palyginimas ir efektyvaus varianto parinkimas. Baigiamajame darbe išnagrinėtos kelios galimos apdailos alternatyvos, kurios pasižymi įrengimo technologijos paprastumu, nedidelėmis darbo sąnaudomis ir kitais privalumais. Palyginti trys gyvenamųjų, visuomeninių ir pramoninių pastatų išorės sienų (fasadų) apdailos įrengimo būdai: tinkavimas, dažymas, dengimas gatavais elementais. Išnagrinėti keli techniniu – ekonominiu požiūriu skirtingi apdailos medžiagų variantai iš kiekvieno apdailos įrengimo būdo. Naudojantis daugiakriteriniais vertinimo metodais bei programos paketu SPS_DS, nustatyti trys racionalūs apdailos medžiagų variantai. Atsižvelgiant į vieno ar kito apdailos medžiagų varianto įgyvendinimo tikslingumą gyvenamojoje, visuomeninėje ar pramoninėje statyboje pateiktos išvados bei pasiūlymai. Darbą sudaro įvadas, 4 skyriai, išvados, literatūros sąrašas. Pirmame skyriuje pateikti bendrieji reikalavimai apdailai, antrame pagrindo dekoratyviniai apdailai paruošimo technologijos analizė, trečiame apdailos įrengimo būdų analizė, ketvirtame racionalaus išorės apdailos varianto parinkimas. Darbo apimtis – 87 p. teksto be priedų, 24 iliustr., 14 lent., 43 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / It is quite obvious, that due to broad variety of finishing materials and functional and architectural purpose of buildings, it is difficult to choose the best façade finishing. Therefore, the topic of master thesis is comparison of finishing materials, and selection of the most effective option. Several possible finishing options were surveyed in the diploma job. Such options are remarkable by its’ technological simplicity, low labour expenditures and other advantage. Three types of inhabitant, public and industrial buildings façades finishing were compared: plastering, painting and coverage with pre-fabricated materials. Several technicallyeconomically different finishing options for each type of finishing were surveyed. Multicriteria evaluation method using SPS-DS software package was used for indicating of three rational finishing options. With regard to the expedience of usage of certain finishing material in private, public and industrial constructions, conclusions and proposals are presented. Thesis consists of Introduction, 4 chapters, Conclusions, References. First chapter includes general requirements for finishing works, second – analysis of preparation of the base for decorative finishing, third – analysis of finishing installation processes, fourth – rational choice between outside finishing options. Scope of thesis – 87 pages of text w/t Annexes, 24 pictures, 14 tables, 43 references. Annexes attached separately.

Much of the existing commercial building stock is aging and will be in need of upgrades now or within the next twenty years. Typically, enclosure retrofits consist of adding insulation to the exterior or interior of the existing façade. In this thesis, an alternative solution is examined, whereby a glass façade is added to the exterior of the existing building, forming a double façade. For historic buildings, this could preserve and protect the existing façade without completely covering it up. For outdated buildings, this could modernize the existing façade, giving it the all-glazed appearance that is currently so popular among architects. Regardless of the retrofit motive, it is important to be able to quantitatively compare retrofit solutions to make informed design decisions. As such, building simulation can be an important design tool. At present, there is no available simulation tool that can easily and accurately model a double façade; therefore, a double façade (DoFa) model was developed to fill this gap. A spreadsheet-based, lumped model was created and validated using current complex fenestration models and limited experimental data. Further experimental data is required to validate all aspects of the model. Results showed that the DoFa model can achieve accurate results; however, further development is needed to predict optical properties of venetian blinds and convective coefficients for natural airflow in double façade cavities. The model was used to compare double façades to traditional glazing systems. Results indicated that double façades can perform comparably to double glazing with outdoor shading in summer, and triple glazing in winter. However, the results are only valid for the tested glazing systems. In a second application, the DoFa model was modified to simulate an entire enclosure to compare a double façade retrofit to more traditional retrofit strategies. Results suggested that a double façade provides a good improvement in winter performance, though summer overheating is a concern. For the case study examined, a double façade would have performed better than the chosen retrofit of replacing the windows with double glazing and indoor shading, without insulating the opaque components. The DoFa model can be very useful in creating double façade preliminary design and operation strategies. At present, the DoFa model is an instantaneous, stand-alone tool. Further development is needed to pair the DoFa model with whole building energy simulations.

In the UK, boom periods of construction combined with typical building styles of the day, have resulted in a large stock of ageing office buildings at risk of structural vacancy and obsolescence. Despite their lack of insulation, high air infiltration, and solar gain, many such buildings from the 1960s-1970s are still in use today. Moreover, with UK buildings replaced at a rate of less than 2% a year, the majority of today's buildings will still be in use in 2050. Due to the impact of the facade on such aspects as thermal performance and aesthetics, façade retrofit is seen as a key solution to the problem of today’s ageing office building stock. Unfortunately, façade retrofit comes with a complex decision-making process. The cost and long-term nature of the investment means that façade decisions are strategic, while the architecture, engineering and construction (AEC) industry is prototypical and multidisciplinary. Decision theory suggests the use of normative decision-making methods to arrive at a well-reasoned course of action; therefore, this thesis aims to discover how decision-making can be improved to support façade selection in non-domestic building retrofit. A state-of-the-art literature review of office building façade retrofit decision-making only returned nine case studies, of which six reported real-life façade retrofit selection. One real-life and one theoretical case demonstrated the use of normative decision-making in the form of the payback period method, while one theoretical case used multi-criteria analysis. Many sources of information were revealed as guiding the façade selection process in general. To examine the actuality of façade selection in practice, an exploratory study was conducted. This study involved (1) semi-structured interviews on the topic of façade selection with thirty UK AEC industry members from twelve professions, and (2) a case study of an over-clad 1970s office building, involving in-depth interviews with two UK AEC industry experts, a documentary evidence review, and post-retrofit thermography. Three semi-structured interviewees revealed the use of normative decision-making, in the form of the payback period method, while information sources were greatly used in general. The exploratory case, however, revealed only a minimal use of information and no normative decision-making. To determine the representativeness of the exploratory case study, an in-depth study of façade retrofit decision-making was conducted. This study involved (1) a specific literature review to set the context of UK university building façade retrofit decision-making and (2) four exemplifying case studies of real-life university building façade retrofit. The university estate features many ageing buildings from the 1960s-1970s that exhibit the same typical building style as the UK’s ageing office stock. The specific literature review found five cases of university façade retrofit decision-making, of which three reported real-life façade retrofit selection. Normative decision-making was revealed in theory, with the two theoretical cases of university façade retrofit using the payback period method. The exemplifying case studies involved eight UK AEC industry experts, a documentary evidence review, and post-retrofit thermography. The case buildings ranged from the late 1950s/early-1960s to the 1970s, with three being over-clad, and one over-clad and re-clad. The exemplifying case study findings support the exploratory case study findings. The key actors in façade retrofit decision-making are the architect, client, and planner. Numerous information sources are used to support the façade selection process, relating chiefly to performance, cost, aesthetics, and collaboration, and the use of normative decision-making is not evident. From the research findings, it appears the process of façade retrofit selection functions naturally within the realm of the architectural profession. Architects appear to be making initial façade design decisions based on ideas resulting from cognition and drawing on past experience, which become more detailed as the project progresses. The façade selection process is supported by the voluntary use of numerous information sources, many of which are quantitative in nature. This thesis did not find evidence of normative decision methods being used in the current practice of façade retrofit selection. Thus, the recommendations proffered are not characteristic of normative theory, but instead opt to support the façade retrofit selection process by reinforcing current process via the following points: (1) use expertise in the form of advisor-led information sources to guide the façade retrofit selection process; (2) maximise communication by encouraging an ongoing dialogue between AEC industry members involved in façade selection, involving specialist external bodies at an early stage, and documenting the façade selection process; and (3) aid the energy efficiency resulting from building retrofit by engaging stakeholders during design, construction, and in-use, especially in regards to proposed new energy efficiency practices. This thesis contributes to the knowledge of non-domestic façade retrofit decision-making in actual building design practice. Having found only limited evidence of normative decision-making being used in the non-domestic façade retrofit selection process, it appears that efforts to develop multi-criteria decision-making tools for use in this area may be misguided.