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Because of the lack of established prototypical models in China, evaluations or predictions of the impact of changes in building codes, appliance and equipment standards, new building technologies, materials, or even design solutions are normally based on particular selected or customized models that vary greatly in different studies, thus jeopardizing the validity of the results. As a step to address this, this study developed a coupled method of the similarity theory and the entropy weight coefficient method to construct prototypical building models that represent the building stock. To present such a constructing method, we adopted apartment buildings in cold climates in China as an example. This research firstly collected a series of architectural design documents of apartment buildings in cold climates in China and performed a statistical analysis of their apartment layout features and other associated design data to achieve a statistical building model. Subsequently, a statistical model was introduced to further simplify the statistical building model's dimensions and thermal properties of the building envelopes and attain the prototypical building models. The effectiveness of the extracted prototypical model for general building energy analysis is presented. Given the availability of design data and surveys, this method of constructing prototypical building models based on the similarity theory can be implemented into other types of building prototypical model development (e.g., office building, single-family house, etc.). [ABSTRACT FROM AUTHOR]

Parametric design and optimization studies have demonstrated high energy savings for dynamic building envelope materials compared to static high-performance envelopes. However, most parametric studies about dynamic buildings were conducted on prototypical buildings with a focus on either optimal geometric settings or idealized material property characteristics, neglecting the potential collective effects of geometric and material design decisions on energy performance. This study investigates the implications of an automated sequential optimization process while designing with dynamic envelope materials. Two case studies were used to quantify energy savings across different optimization-based design procedures and identify the relative importance of various decision categories. When considering realistic design constraints and intrinsic material limitations, geometric optimization alone yielded only 2% energy savings, while dynamic material optimization savings reached up to 19%. Significantly, a sequential design process in which the geometry is configured first before the façade is optimized and vice versa can lead to around 5% missed energy savings. These findings encourage changes to traditional design guidelines and simulation-based building design approaches when working with dynamic façades. • Optimizing facade materials yields more energy savings than optimizing geometry. • Sequential optimization for facade geometry and materials can reduce energy savings. • Of individual design variables, window-to-wall ratio has most effect on energy use. • Yet with daylight requirements, altering material properties enables lower energy. [ABSTRACT FROM AUTHOR]

The photovoltaic double skin façade (PV-DSF) represents the frontier of the advanced building envelope, whereas the prior parameter analysis had predominantly focused on the influence of individual factors. As two essential factors of PV-DSF, the photovoltaic etching ratio ϑ and cavity depth D cav have garnered considerable academic attention, with little of them focusing on their coupling effect to energy performance. This paper investigates the impact of ϑ and D cav using a spectrum-resolution numerical model, incorporating the concept of elementary effects derived from Morris method to quantify their interaction. The findings reveal that ϑ exhibits a non-monotonic impact, whereas the influence of D cav is monotonic but non-linear. The optimal ϑ is found to be within the range of 30–50 %, while the lowest D cav mostly outperforms other values, contrary to previous studies. This deviation is speculated to arise from the consideration of hot air generation energy. Furthermore, the variation of one factor can potentially alter the optimal value of the other. The second-order elementary effect between them demonstrates that their coupling effect is also non-linear and non-monotonic, with an impact as significant as that of D cav alone. Overall, the correlations between ϑ and D cav should be thoroughly considered during the design period. [ABSTRACT FROM AUTHOR]

The photovoltaic double skin façade (PV-DSF) is a cutting-edge building envelope renowned for its dynamic nature and power generation capabilities, which attracts substantial scientific attention. However, the current lack of experimental support makes it challenging to draw definitive conclusions about the influence of façade material. This study aims to address this gap by investigating the energy performance of PV-DSF with different façade materials, thereby establishing an empirical foundation for its optimization. In this regard, the full-size comparison experiments on PV-DSF with 20/40% photovoltaic (PV) glass as external façade and laminated/double glass as internal glass were conducted in Harbin, China. The EnergyPlus software is adopted for the simulation of lighting energy consumption. The results indicate that PV-DSF with 40% PV outperforms that with 20% PV, leading to significant reductions in total energy consumption in both summer (22.73%) and winter (16.84%). The double glass can prevent 0.49 MJ of total heat gain in summer, which is accompanied by a marginal 0.03 MJ increase in winter energy consumption. In total, for optimal annual performance, 40% PV and double glass are recommended as the façades of PV-DSF. The results of this investigation can provide an experimental foundation for PV-DSF optimization in sustainable building design. • This paper presents the semi-experimental study on photovoltaic double skin façade. • The impact of façade material on the net energy-saving performance is studied. • The 40% photovoltaic (PV) glass outperforms 20% PV glass in both summer and winter. • The double glass possesses great advantage in summer, with a tiny short in winter. • From the view of year-round operation, 40% PV and double glass are recommended. [ABSTRACT FROM AUTHOR]