Research on Micro-Intervention Strategies for Energy-Saving Renovation of the Envelope Structures in Existing Brick–Wood Ancient-Style Buildings

In the global low-carbon era, building energy conservation has achieved significant success. However, especially in the culture and tourism industry, there are many brick–wood buildings that imitate ancient styles. As their appearance authenticity and structural safety must be maintained, energy-saving retrofits face multiple constraints. For such buildings, regulating building energy consumption through the renovation of the enclosure structure has practical value in supporting the achievement of carbon peaking and carbon neutrality goals. This study addresses the contradiction between the preserving architectural forms and improving energy efficiency in the energy-saving renovation of brick–wood buildings that imitate ancient styles. It presents a “Three-Micro” technical system grounded in the minimum-intervention principle, integrating micro-intervention implantation, micro-realignment regulation, and micro-renewal iteration. Through modular node design, it combines traditional construction with modern energy-saving techniques and systematically devises an energy-saving retrofit plan for such existing buildings. Through simulation and verification using the case of the Northwest Corner Tower in the Imperial City of Shengjing, the results show that the energy-saving rate of the building itself is 58.47%, while the comprehensive energy-saving rate is 87.56%. Both meet the evaluation criteria for ultra-low energy consumption buildings under the relevant standards, which proves the feasibility of the “Three-Micro” technical system. It provides solutions for the energy-saving renovation of similar buildings, especially those brick–wood buildings that imitate ancient styles and have a high degree of completion (a high level of imitation of ancient architecture). At the same time, it also holds important reference value for the energy-saving renovation of some non-core ancient buildings that are commonly used in everyday life, such as those serving as ticket offices, exhibition halls, administrative offices, etc.