## 3 Methodology
### Parametric Urban Block Morphology Intelligent Generation  
This study investigates 340 typical elderly residential buildings in Beijing, covering basic information such as building types, building heights, block scale, and road dimensions. Through the survey, 9 types of elderly residential buildings were identified (Figure 3). Based on building type, they were categorized into point-type (P-1, P-2, P-3), slab-type (S-1, S-2, S-3), and enclosed-type (C-1, C-2, C-3) buildings [48; 68]. They were also divided into three building height categories, as follows: 1-3 stories (S-1, C-2, P-1), 4-9 stories (S-2, C-1, C-3), and 10-18 stories (S-3, P-2, P-3). Based on the scale of typical elderly residential blocks, a 90 \(\times\) 90 m square unit was selected as the basic block (with a street width of 10 m). A 330 \(\times\) 330 m urban block was generated through a 3 \(\times\) 3 modular configuration, with 9 basic blocks numbered from 0 to 8. Each basic block was required to contain only one building-type unit. In this study, a total of 10 building types were available for combination, including the 9 types of elderly residential buildings identified in the survey and 1 type of urban public space. A parametric  
Figure 2: Study area and distribution of survey points. model of the block morphology was constructed within the Rhino/Grasshopper platform. By combining different building forms in different basic blocks, a diversified parametric urban block model was generated. Figure 4 shows the process of generating the urban block parametric model by combining the 9 building types and 1 public space extracted in this study. Sixteen morphological indicators, which have been proven in previous studies to be related to outdoor environmental performance, were selected to describe the generated parametric urban block models. These included average building height (AH), standard deviation of building height (StdH), Distance Between Buildings (DB), building density (BD), floor-area ratio (FAR), Volume-Area Ratio (VAR), Space Crowding Density (SCD), porosity (PO), Shape Coefficient (SC), perimeter-area ratio (PAR), Mean Building Area (MA), Standard Deviation of Building Area (SA), Average Building Volume (AV), Standard Deviation of Building Volume (SV), Open Space Ratio (OSR), and Coefficient of Variation for Building Height (CVH) [48; 69; 70]. The block morphology information described by these indicators is shown in Figure 5.  
Figure 4: Neighborhood generation process. Figure 3: Building type simplification with specific modeling parameters. (The figure shows the information of nine different types of buildings, including axonometric drawings (on the left), floor plans (on the upper right), and elevation drawings (on the lower right)). AH and StdH refer to the average building height and the standard deviation of building heights within the block, respectively. BD and FAR are critical indicators for urban block morphology and are essential in early urban planning. BD measures the proportion of the block area covered by buildings, while FAR reflects the total building area relative to the block area. High-density and high-intensity development often reduce wind speed, impacting thermal comfort. DB, calculated as the average distance between building centers, reflects block compactness or sprawl. Its impact on thermal comfort and sunlight exposure has received limited attention. VAR, the ratio of total building volume to site area, indicates land-use efficiency. While a higher VAR suggests better land utilization, excessive values can create environmental issues. SCD, the ratio of total building volume to the product of block area and tallest building height, measures indoor space efficiency. PO, the void-to-canopy volume ratio, assesses ventilation potential. SC, the surface-to-volume ratio of buildings, evaluates form complexity and energy efficiency, with a higher SC potentially increasing heat transfer. PAR, the perimeter-to-area ratio, highlights block compactness and permeability, with higher values indicating denser blocks.