Qinghai Province urgently requires the development of adaptive energy-efficient rural housing construction to address resettlement needs arising from hydropower projects, given the region’s characteristic combination of high solar irradiance resources and severe cold climate conditions. This research establishes localized retrofit strategies through systematic field investigations and Rhinoceros modeling simulations of five representative rural residences across four villages. The key findings reveal that comprehensive building envelope retrofits achieve an 80% reduction in energy consumption. South-facing sunspaces demonstrate effective thermal buffering capacity, though their spatial depth exhibits negligible correlation with heating energy requirements. An optimized hybrid shading system combining roof overhangs and vertical louvers demonstrates critical efficacy in summer overheating mitigation, with vertical louvers demonstrating superior thermal and luminous regulation precision. Architectural orientation analysis identifies an optimal alignment within ±10° of true south, emphasizing the functional zoning principle of positioning primary living spaces in south-oriented ground floor areas while locating auxiliary functions in northeastern/northwestern zones. The integrated design framework synergizes three core components: passive solar optimization, climate-responsive shading mechanisms, and performance-enhanced envelope systems, achieving simultaneous improvements in energy efficiency and thermal comfort within resettlement housing constraints. This methodology establishes a replicable paradigm for climate-resilient rural architecture in high-altitude, solar-intensive cold regions, effectively reconciling community reconstruction needs with low-carbon development imperatives through context-specific technical solutions.

Solar exposure and shading critically influence outdoor thermal comfort in residential areas, yet quantitative links between spatial morphology and microclimate remain insufficiently explored in cold-region cities. This study proposes a novel morphological indicator, the Insolation Shadow Ratio (ISR), to quantify sunlight–shade dynamics and investigates its correlation with outdoor thermal comfort (UTCI) in Xi’an, China. Combining field observations, microclimate simulations, and statistical analysis, we quantified ISR and UTCI across three representative outdoor spaces in a residential area. Photographic analysis and spatial parameterization were employed to calculate hourly ISR values. Significant correlations were observed between ISR and UTCI values. The measured data showed the strongest correlation at summer solstice at site C (Spearman’s r = 0.883, p < 0.01). GAM analysis of seasonal peak correlation data revealed that an optimal UTCI comfort range of 9 °C to 26 °C, corresponding to ISR thresholds of 0.0202–0.8384, achieved the highest autumn correlation at site C (r = 0.686, p < 0.01), while effectively balancing shade cooling effects and solar accessibility. The ISR framework provides a quantifiable tool for designers to optimize outdoor thermal environments and, when enhanced by parametric modeling tools, enables them to proactively optimize thermal performance during early-stage residential planning, offering a data-driven pathway for climate-resilient outdoor space design.