In the context of food security in mountain regions, this study explores the potential of a Smart Greenhouse (SGH) to address the challenges posed by climate change and limited resources. The SGH utilizes an 8 m² solar water heating system, weather stations for external temperature and humidity monitoring, as well as internal light, humidity, and temperature sensors to create an optimized environment for crop cultivation. Experiments were conducted with various crops within the SGH during the harsh winter months, typically rendering the cultivable land fallow due to extreme cold conditions. The SGH is equipped with sensors and communication technologies, ensuring continuous data collection and the automated regulation of heating, ventilation, and air conditioning systems. Located in Genekha, Thimphu, this pilot SGH seamlessly integrates renewable energy technology to provide heat during the cold winter season, obviating the need for external heating sources in the summer. The study employed TRNSYS and OpenStudio simulation software to assess the SGH’s performance, focusing on temperature and humidity control inside and outside the greenhouse. Additionally, soil pH and nutrient content were examined, and the time required for crop growth and harvesting was recorded. In conclusion, this paper acknowledges some of the current design’s limitations and presents recommendations for future enhancements, with a focus on the specific context of improving crop production and food security in mountainous regions.