## 5 Conclusions
In contrast, more complex building forms hinder natural ventilation in the block, leading to heat accumulation and an increase in surrounding temperatures, thereby exacerbating discomfort. In terms of winter outdoor thermal comfort, indicators such as higher block porosity and building form coefficient significantly reduce the winter outdoor UTCI value, while a higher average building height, volume density, and FAR significantly increase the winter outdoor UTCI value. This may be because increasing the block porosity and building form coefficient makes it difficult for the same block to block cold air in winter, leaving outdoor spaces exposed to cold winds and low temperatures, thereby lowering winter thermal comfort. Conversely, more concentrated building layouts and taller buildings help the block resist more cold winds in winter, resulting in heat accumulation and a rise in surrounding temperatures, improving winter thermal comfort for seniors. In terms of sunlight duration, a higher average building height, larger average building footprint, and larger FAR significantly reduce the sunlight duration. This is consistent with human experience and previous research: increasing building height, footprint, and FAR results in more shadowing within the same block scale, reducing the opportunity for seniors to receive sunlight. Through the interpretation of the three sets of machine learning model results, it can be observed that the effects of different morphological indicators on different outdoor environmental performances are somewhat contradictory. Especially in the context of Beijing's cold winter and hot summer climate, increasing building density and FAR to enhance block coherence and reduce heat loss caused by winter cold winds while creating a more comfortable outdoor thermal environment may suppress natural ventilation in summer, thereby reducing summer outdoor thermal comfort. Similarly, increasing the average building height to create more shadowed areas may also result in a loss of some sunlight duration. In the past, designers have often relied on their own experience to guide urban design decisions, but this workflow has been proven to be inefficient. This study, by combining parametric platforms with genetic algorithms, transforms the process into a quantifiable and controllable parametric design workflow, while exploring the morphological indicators affecting outdoor environmental performance to help designers focus on key aspects in early-stage decisions, improving work efficiency. Based on the findings, the following design recommendations for climate-responsive block morphology are proposed:  
1. High-rise buildings should be set on the north side of the block to ensure a high floor-area ratio while blocking winter cold winds. 2. Mid-to-high-rise buildings should be placed on the west side of the block to maintain natural ventilation in summer while reducing the impact of westward heat. 3. Low-rise buildings should be placed on the east and south sides to ensure direct sunlight penetration and increase sunlight hours. 4. The overall block layout should be considered, forming an enclosed shape with higher buildings on the outside and lower buildings on the inside, following the northwest high, southeast-low principle, to ensure comfortable outdoor environments within the block. 5. The building forms should be simple, reducing the form factor, and clustered building types should be prioritized. This study has the following contributions: 1. A \"pre-evaluation\" optimization framework considering outdoor comfort and lighting duration was applied to the shape design of the elderly block in cold areas, filling the gap in the quantitative study of the elderly block shape. 2. Through field research, performance simulation, and data analytics, the nonlinear relationship between the block shape of elderly residential buildings and environmental performance indicators was explained, and the key factors affecting elderly people's outdoor environmental experience were accurately identified. 3.