With the continuous improvement in people’s quality of life, the energy consumption and carbon emissions from residential buildings under traditional energy production methods have been increasing. Existing residential buildings, due to era of construction and energy consumption loss during operation, are often found to fail to meet current living standards and thus are recognized as having significant potential for retrofitting. The application of photovoltaic and solar thermal technologies is acknowledged as offering substantial potential for carbon reduction. However, in cold zone, the significant seasonal variations of heating and air conditioning energy consumption, as well as solar energy resources, make it difficult for the high emission reduction potential of existing residential areas to be matched with low investment costs. Furthermore, in previous studies, a sequential relationship between active and passive building technologies was typically shown, with passive retrofitting being followed by the installation of active systems for maximum energy efficiency. However, the optimization of the sequence of active and passive technologies in residential buildings can lead to resource wastage, issues of overlap and poor compatibility between different types of energy efficiency technologies are often encountered. Therefore, for existing residential buildings, research and analysis on the coordinated use of both active and passive energy efficiency measures are urgently needed to be conducted. This study aims to address issues such as large inventory, high energy consumption, and poor indoor thermal environment of existing residential community in cold zone of China.In this paper, urban residential buildings in cold zone were focused on, with basic building information being gathered through surveys and analyses, and Yunshanli Community was identified as a typical residential community. Using the Grasshopper platform, a basic model of the selected typical existing residential community was built, with the constraints of active and passive technologies being defined. The study then involves the analysis of the lifecycle investment and the lifecycle carbon emissions of the selected building technologies, with the process being optimized for environmental benefit, economic benefit, and predicted percentage of dissatisfied during the retrofitting process, leading to the proposal of an optimal low-carbon retrofitting plan for existing residential buildings in cold zone. The results show that: 1) In the decision-making stage of low-carbon transformation, the weight of environmental benefit, economic benefit and predicted percentage of dissatisfied are 24.46%, 30.25% and 45.28% respectively. The primary consideration for low-carbon retrofitting is identified as the predicted percentage of dissatisfied, followed by the economic benefit, while the environmental benefit is usually the least considered. 2) In theoptimization results of passive technologies, the key parameters for existing residential buildings in cold zone were found to include a 0.12 m thickness for external wall insulation, 0.10 m thickness for roof insulation, XPS as the material for external wall insulation, rock wool board for roof insulation, and 12 mm thick transparent glass. In active technology optimization, the south-facing photovoltaic panel angle is 2°, the west-facing photovoltaic panel angle is 0°, with 5 floors of photovoltaic panels being used, photovoltaic and solar thermal system angle is set at 0° on the roof, and photovoltaic panel area ratio is 0.5 on the roof. Compared with the typical model, the incremental environmental benefit of life cycle retrofit after optimization is 355.06 kgCO2/m2, the incremental economic benefit of life cycle retrofit is 1 197.75 yuan/m2 and the predicted percentage of dissatisfied is 16.8% with a reduction of 10%. Therefore, the active-passive coupled parallel optimization approach has broad application prospects in the design of low-carbon retrofitting of existing residential community.An in-depth study on the retrofitting of existing residential community buildings was conducted in this paper. A design procedure for low-carbon retrofitting, which combines model extraction, performance prediction, and strategy optimization, was established for existing residential community buildings. The interaction between active and passive technologies was enhanced, leading to increased energy efficiency in buildings and reduced carbon emissions, and simultaneously ensuring economic viability and comfort. The maximization of retrofitting benefits were achieved, and an optimization method and strategy for the low-carbon retrofitting of existing residential area buildings based on the coupling of active and passive technologies were developed. It provides theoretical support and strategic references for the renewal and retrofitting of existing residential community and the coupled application of active and passive energy efficiency technologies.