Building facades play an important role in thermal loads, which act as an isolation barrier to ensure thermal comfort to the occupants. Depending on the properties of the building material adopted, each component of a building facade may lose or gain heat, contributing to the building's thermal load. There is a growing need to examine the role that external construction components play from an energy perspective towards achieving environmental comfort in buildings. The novelty of this research is to propose a methodological framework based on Design of Experiments (DOE) that characterizes the thermal loads that are directly caused by variables controlled by building designers and consultants. Such variables include external construction components (walls and openings assessed via window-to-wall ratio), air infiltration rate, artificial lighting, occupation levels, heating, and cooling equipment, and appliances during the operation phase of a building, taking into consideration the local climate data in which the building is located. This work validates the proposed method with a case study of a single-family house, which provides a better understanding of the influence and interactions of design factors on building thermal loads. Results reveal that the window-to-wall ratio has a major influence on evaluating the thermal loads in buildings. The higher the ratio, the higher the value of the thermal loads. The proposed framework aids designers in determining the components that are influencing thermal loads in buildings, as well as the required window-to-wall ratio. Findings highlight that construction components of external walls and openings are responsible for around 93.9 – 97.58% of thermal loads in buildings. Furthermore, this work presents the important role of sustainable building decisions at an early stage of designing construction projects.

建筑立面在热负荷中起着重要作用，热负荷充当隔离屏障，以确保居住者的热舒适感。根据所采用的建筑材料的特性，建筑物外墙的每个组件可能会散失或吸收热量，从而增加建筑物的热负荷。从能源的角度出发，越来越需要研究外部建筑组件在实现建筑物的环境舒适性方面的作用。这项研究的新颖性在于提出一种基于实验设计（DOE）的方法框架，该框架描述了由建筑设计师和顾问控制的变量直接引起的热负荷。此类变量包括外部建筑组件（通过窗户与墙壁的比例评估的墙壁和开口），空气渗透率，在建筑物运营阶段要考虑人工照明，占用水平，供暖和制冷设备以及家用电器，同时要考虑建筑物所在的当地气候数据。这项工作通过对单户住宅的案例研究验证了所提出的方法，该案例可以更好地理解设计因素对建筑物热负荷的影响和相互作用。结果表明，窗墙比对评估建筑物中的热负荷具有重要影响。比率越高，热负荷的值越高。拟议的框架可帮助设计人员确定影响建筑物热负荷的组件以及所需的窗墙比。调查结果突出表明，外墙和开口的建筑构件约占建筑物热负荷的93.9 – 97.58％。此外，这项工作在设计建筑项目的早期阶段就提出了可持续建筑决策的重要作用。