In recent times data-driven approaches to parametrically optimize and explore building geometry has been proven to be a powerful tool that can replace computationally expensive and time-consuming simulations for energy prediction in the early design process. In this research, we explore the use of surrogate models, i.e. efficient statistical approximations of expensive physics-based building simulation models, to lower the computational burden of large-scale building geometry analysis. We try different approaches and techniques to train a machine learning model using multiple datasets to analyze the impact of geometry and envelope features on the energy efficiency of buildings. These contributions are presented in the form of two conference papers and one journal paper (being prepared for submission) that iteratively build up the underlying methodology. The first conference paper contains preliminary experiments using 4 manually generated building geometries for office buildings. Data were generated by simulating various building samples in EnergyPlus for different geometries. We used the generated data to train a machine learning model using support vector regression. We trained two separate models for predicting heating and cooling loads. The lesson learned from this first experiment was that the prediction of the models was not great due to insufficient geometric features explaining the variability in geometry and the lack of sufficient data for varied geometries. The second conference paper developed a novel dataset of 38,000 building energy models for varied geometry using 2D images of real-world residences. We developed a workflow in the Grasshopper/Rhino environment which can convert 2D images of a floor plan into a vector format then into a building energy model ready to be simulated in EnergyPlus. The workflow can also extract up to 20 geometric features from the model, to be used as features in the machine learning process. We used these features and the simulation results to train a neural network-based surrogate model. A sensitivity analysis was performed to understand the impact and importance of each feature to the energy use of the building. From the results of the experiment, we found that off-the-shelf neural network-based surrogates provided with engineered features can very well emulate the desired simulation outputs. We also repeated the experiment for 6 different climatic zones across Canada to understand the impact of geometric features across various climates; these findings are presented in an appendix. iv In the journal paper, we explored two different methodologies to train surrogate models: monolithic and component-based. We explored the component-based modeling technique as it allows the model to be more versatile if we need to add more components to it, ultimately increasing the usability of the model. We conducted further experiments by adding complexity to the geometry surrogate model. We introduced 10 envelope features as an input to the surrogate along with the 20 geometric features. We trained 6 different surrogate models using different datasets by varying geometric and envelope features. From the results of the experiment, we found that the monolithic model performs the best but the component-based surrogate also falls into an acceptable range of accuracy. From the overall results across the three papers, we see that simple neural network-based surrogate models perform really well to emulate simulation outcomes over a wide variety of geometries and envelope features / Graduate

Orientador: Luzia Aparecida Trinca / Resumo: Nas mais diversas áreas do conhecimento se procura aumentar a eficiência dos delineamentos experimentais, principalmente, para minimizar os custos das pesquisas. O uso dos delineamentos ótimos, com seus diferentes critérios de otimização, é fundamental para se obter resultados que maximizam a informação em estudos experimentais. A maioria dos métodos pressupõe homogeneidade de variâncias, a qual nem sempre é veri cada no conjunto de dados. O objetivo deste trabalho é desenvolver uma metodologia para construção de delineamentos ótimos exatos e cientes em situações de variância não homogênea. Assume-se que linearidade e homoscedasticidade são obtidas via o uso de transformações da família Box-Cox e, além de critérios de otimização puros, critérios compostos que combinam duas propriedades são propostos. Resultados para vários exemplos sob os modelos de primeira e segunda ordem são obtidos e discutidos. / Abstract: In several areas of knowledge we seek to increase the efficiency of experimental designs, mainly in order to minimize the costs of reaserch. The use of optimal design with different optimization criteria is fundamental to obtain results that maximize the information in experimental studies. Most of the methods assume homogeneity of variances, which is not always verified in the data set. The goal of this work is to develop a methodology to construct exact optimal or efficient designs in situations of nonhomogeneous variance. It is assumed that application of a transformation from the Box-Cox family accomplish both linearity and homocedasticity. Pure design criterion as well as compound criteria using two desired properties are used. Results for several examples assuming first and second order models are presented and discussed. / Doutor