Heat Inequities in Suburban Development: A Deep Learning Analysis of Built Form and Vegetation

Rapid urban population growth has led to extensive residential expansion, particularly in the suburbs of major metropolitan areas. The morphology and landscape structure of these residential environments play a key role in regulating their local thermal conditions. This study examines thermal differences between newly developed and older single-family middle-class suburban neighborhoods in Los Angeles, CA, at the urban block scale through the integration of aerial and street level imagery and the application of deep learning techniques for feature extraction and analysis. The results show that the mean summer temperature in newly developed suburban neighborhoods is 4.2 °C higher than in older suburban neighborhoods. Morphological and landscape analyses also reveal key differences in building and vegetation structure between the two suburban neighborhood types. Older suburban neighborhoods exhibit, on average, 27% lower lot coverage and 23% greater spacing between buildings compared to newly developed neighborhoods, providing more open space for vegetation cover. Street trees and backyard trees in these older neighborhoods are generally taller, more mature, and characterized by broad canopies, and they provide effective shading and cooling across both public domains (streets and sidewalks) and private/semi-private domains (backyards and inter-building spaces). By contrast, newly developed neighborhoods, alongside their greater lot coverage, show reduced vegetation cover. Existing trees are often young, short, and unable to provide effective shade, and a large share of the vegetated area is covered by grass, with limited capacity for temperature moderation. These morphological and landscape contrasts indicate that newly developed neighborhoods have lower cooling potential. Overall, the study emphasizes the importance of residential morphology and the type, maturity, and spatial distribution of vegetation across both public and private realms in reducing summer temperatures. The findings may inform revisions to future development guidelines and urban forest management plans, and may encourage planners, developers, and residents to adopt innovative cooling initiatives to help mitigate urban summer heat.