This paper aims to better understand how building density and shape jointly influence building energy performance in downtown urban environments. Three research questions are addressed: (1) How does the building density influence energy performance? (2) Given the same density, how do different building cover ratios create different impacts on energy performance? And,(3) How do different building typologies affect the density–energy relationship? To explore these questions, a series of parametric simulation experiments were conducted based on a hypothetical urban block structure that mimics the downtown urban grid of Portland. Energy use intensities of the office buildings with fully controlled environments are simulated. In contrast to the hypothesis that energy performance would be enhanced by increasing density, the results suggest that building energy use intensity decreases when density increases to a certain point and then begins to increase. Such a pattern suggests a threshold density that has the minimum building energy use intensity, while other parameters are constant. The study also explores how different building shapes generated with different cover ratio values and building typologies perform in terms of building energy performance, given the same density. Additional experiments extend the findings from Portland to downtown Atlanta and show similar patterns.

中文翻译：

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密度与建筑节能性能关系的探索

本文旨在更好地了解建筑密度和形状如何共同影响市中心城市环境中的建筑能源性能。解决了三个研究问题：(1) 建筑密度如何影响能源性能？(2) 在密度相同的情况下，不同的建筑覆盖率如何对能源性能产生不同的影响？并且，(3) 不同的建筑类型如何影响密度-能量关系？为了探索这些问题，基于模拟波特兰市中心城市网格的假设城市街区结构进行了一系列参数化模拟实验。模拟了环境完全受控的办公楼的能源使用强度。与通过增加密度提高能源性能的假设相反，结果表明，当密度增加到一定程度后，建筑能源使用强度降低，然后开始增加。这种模式表明具有最小建筑能源使用强度的阈值密度，而其他参数是恒定的。该研究还探讨了在相同密度的情况下，使用不同覆盖率值和建筑类型生成的不同建筑形状在建筑能源性能方面的表现。其他实验将调查结果从波特兰扩展到亚特兰大市中心，并显示出类似的模式。该研究还探讨了在相同密度的情况下，使用不同覆盖率值和建筑类型生成的不同建筑形状在建筑能源性能方面的表现。其他实验将调查结果从波特兰扩展到亚特兰大市中心，并显示出类似的模式。该研究还探讨了在相同密度的情况下，使用不同覆盖率值和建筑类型生成的不同建筑形状在建筑能源性能方面的表现。其他实验将调查结果从波特兰扩展到亚特兰大市中心，并显示出类似的模式。