This study reviews the global trends, developments, and challenges in the conservation of historic districts through CiteSpace analysis. Since the dawn of the 21st century, research on historic districts has witnessed rapid growth. The research mainly focuses on fields such as urban studies, heritage conservation, and sustainable development. Although the concept of the Historic Urban Landscape has emerged, its local application remains challenging. Research findings on economic impacts are complex, and resilience assessment and community participation have become important topics. However, issues like inconsistent definitions and low community participation still exist. Future research should focus on narrowing the gap between theory and practice to better protect cultural heritage in the context of urban development.

With the acceleration of urbanisation and the increased utilisation of underground space, providing a comfortable and healthy environment in public underground areas has emerged as a significant research topic. This study constructs a comprehensive decision-making framework for underground space environments by integrating human perception evaluations with physical environmental parameters. Using Shanghai Wujiaochang as a case study, field data collection and questionnaire surveys were conducted to evaluate key factors such as temperature (22.63 °C–26.39 °C), wind speed (0.26 m/s–0.67 m/s), and sound levels (59.68 dB–61.21 dB) for commercial-oriented spaces, and 63.15 dB–75.45 dB for transport-oriented spaces) to users’ perceived experiences. The appropriate ranges for key parameters were identified through single-indicator fitted regression analysis and the XGBoost machine-learning model, revealing the relationship between environmental parameters and human perception. The results indicated significant differences in user needs across various functional spaces, with commercial-oriented areas emphasising environmental attractiveness and comfort, while transport-oriented spaces prioritised access efficiency and safety. This study provided quantitative design benchmarks for underground spaces’ dynamic regulation and sustainable management, proposing a precise and adaptive environmental decision-making framework that combines physical parameters with user-perception feedback.

This study focuses on buildings in the Chinese–Baroque Historic Shopping District in Harbin. In view of global climate change and high carbon emissions from the construction industry, this study aims to quantify carbon emissions during the decoration process and explore low-carbon decoration strategies that suit the local characteristics. This research adopts a four-stage framework of “data collection–quantitative analysis–strategy design–verification and optimization” and integrates Life Cycle Assessment (LCA) and multi-objective optimization theory. Data are collected through questionnaires and field investigations, and simulations and analyses are carried out using Grasshopper and Honeybee. The results show that there are differences in carbon emissions between different decoration schemes. The chosen scheme of raw concrete and paint results in relatively low carbon emissions over the 10.12-year usage cycle. Based on this, design strategies such as extending the service life of decorations, rationally renovating windows, and preferentially selecting local low-carbon materials are proposed and applied to practical projects. This study not only fills a gap in the research on the low-carbon renovation of historical commercial blocks from the perspective of LCA but also provides practical solutions for the sustainable development of historical shopping blocks in Harbin and similar regions, promoting the low-carbon transformation of cities.

Against the backdrop of global rural decline and China’s Rural Revitalization Strategy (2017–2050), this study examines the spatial form evolution and development mechanism of Central Village in Huotong Town, Ningde. To achieve this, it employs field surveys, spatial mapping, and hierarchical element analysis to analyze the village’s scale, architectural texture, street interfaces, and landscape nodes. Results show three evolutionary stages: pre-2017 traffic-guided disorderly expansion, 2017–2020 policy-driven orderly planning, and post-2020 stock optimization, forming an “oval radial” structure constrained by the southern hills and Huotong River. The spatial structure shifted from a “kinship-based agglomeration” to a multi-center model, yet contradictions like historical texture damage and excessive street commercialization emerged. Its development is driven by four linked factors: policy, the market, socio-culture issues, and nature. This study offers references for similar rural settlements’ spatial planning and sustainability.

With the acceleration of urbanisation and the increase in underground space use, how to provide a comfortable and healthy environment in underground space has become an important research topic. This study constructed an environmental decision-making model for underground space by integrating human perception evaluation and physical environment factors. The study analysed the influence of physical environment parameters on users' perceived experience through field data collection and questionnaire surveys. The data were in-depth analysed using single-indicator fitted regression analysis and XGBoost machine learning model. The results reveal the significant influence of physical parameters such as temperature, humidity, illuminance and wind speed on the comfort of users of underground spaces and determine the range of appropriateness of these physical environment parameters. The results provide a reliable theoretical basis for optimising the design and management of underground spaces and help to enhance the environmental quality and user experience of underground spaces.