Because several buildings constructed in the process of urbanization are aged, several countries in the EU have been aware of the problems in terms of the energy consumption and greenhouse gas emissions of these existing buildings. To address these problems, various studies have been conducted to determine an improvement method for the energy performance of aged buildings by adopting the smart city concept. However, because they have primarily focused on the software aspects of monitoring and control using IT technologies, studies on the hardware aspects (that is, the characteristics of buildings and renovation techniques for energy saving) that affect energy performance have been underrepresented in the context of smart cities. Therefore, by using the structural equation modeling (SEM) technique, this study aims to analyze the causal relationship by examining how the characteristics of buildings and energy-saving techniques affect the energy performance of EU smart city projects. To implement SEM for depicting causal relationships, a case study based on 55 building cases on 11 EU smart city projects was conducted, and the significant direct/indirect effects of hardware aspects on energy-saving performance were successfully suggested.

由于在城市化过程中建造的几座建筑已经老化，欧盟多个国家已经意识到这些既有建筑在能源消耗和温室气体排放方面存在的问题。为了解决这些问题，已经进行了各种研究，以确定通过采用智慧城市概念来改善老建筑能源性能的方法。然而，由于它们主要集中在使用 IT 技术进行监控和控制的软件方面，因此对影响能源性能的硬件方面（即建筑物的特性和节能改造技术）的研究在智慧城市。因此，通过使用结构方程模型 (SEM) 技术，本研究旨在通过检查建筑物的特征和节能技术如何影响欧盟智慧城市项目的能源绩效来分析因果关系。为了实施 SEM 描述因果关系，基于 11 个欧盟智慧城市项目的 55 个建筑案例进行了案例研究，并成功提出了硬件方面对节能性能的显着直接/间接影响。