Optimizing thermal environments in traditional vernacular dwellings of Beijing’s western shallow mountains: balancing energy efficiency and heritage conservation with air source heat pump heating

This study investigates methods to improve heating in traditional stone-slab houses in Beijing’s western shallow mountains, while preserving their cultural heritage and aligning with China’s objectives for sustainable energy and rural revitalization. Using surveys, field measurements, material tests, and computer simulations, we examined air source heat pump (ASHP) systems in combination with building upgrades, such as internal insulation and improved windows. Our findings indicate that traditional materials, such as rammed earth-stone walls and slate roofs, possess natural heat-retaining properties. By adding internal insulation (e.g., 50 mm polyurethane or extruded polystyrene) and triple-glazed windows, we improved winter indoor temperatures by a maximum of 4.92 °C and reduced energy use by 27.97–36.32 %, with costs recoverable in as little as 4.75 years. These upgrades avoid altering the buildings’ historic appearance, balancing energy efficiency with heritage preservation. This work presents a practical model for upgrading traditional rural homes, which supports both environmental goals and cultural conservation.