This study examines the sustainability of vernacular housing architecture in the cold climate of East Azerbaijan, focusing on Varzeghan County. The main objective is to assess the sustainability of structural, material, spatial, socio-cultural, and economic aspects in ten selected villages, including Vardin, Kasin, Alvigh, Chaykandi, Dehlin, Alvigh, Kalan, Kheyraddin, Khoynarud, and Venestan, and to provide strategies for improvement. The research employs a descriptive-analytical approach using the PLS model, considering the weighted influence (β) of five key constructs: Caleb–Climate, Materials, Spatial Organization, Culture–Society, and Economy. Results indicate that Vardin and Kasin achieved the highest sustainability scores (4.75 and 4.38 respectively) due to coherent spatial organization, durable materials, and full compliance with climatic and cultural patterns. Villages such as Alvigh, Chaykandi, and Dehlin showed moderate performance due to relative weaknesses in material durability and structural cohesion, while Venestan, Khoynarud, and Kheyraddin ranked lowest (1.75–2.10) due to dispersed layouts and poor adaptation to climatic and cultural patterns. The findings emphasize that strengthening structural and material dimensions, alongside improving spatial organization and supporting socio-cultural elements, is essential for achieving long-term sustainability. Limitations include the lack of precise field data and reliance on relative assessments and theoretical modeling. It is recommended that reconstruction and conservation initiatives focus on material and structural enhancement, spatial organization improvement, community training in local materials, and economic incentives for building maintenance to ensure sustainable vernacular architecture in Varzeghan villages.