Energy Saving and Thermal Comfort Performance of Passive Retrofitting Measures for Traditional Rammed Earth House in Lingnan, China

The traditional rammed earth houses sharing similar patterns in the Lingnan region, south China, and distributed in rectangular arrays, are gradually losing their vitality and becoming uninhabited under modern living conditions. This research examined a typical pattern called the “Four-point gold” house and analyzed the suitability of different retrofitting technologies by field measurements and building simulation. To optimize energy consumption, indoor thermal comfort, and the corresponding economic performance of the retrofitting measures for the prototypical house, five measures, including wall insulation, reflective roof coating, carpet, sunshade, and natural ventilation, are proposed after considering the status quo of the building envelope. It is found that the best performance in energy-saving, dynamic investment payback period, and annual indoor thermal comfort are 2192.27 kWh/a, 9.17 years, and 1766 h, respectively. Different parameters are included to be clustered by K means clustering technique, and the comprehensively optimized scheme consists of a regime of 30 mm XPS 30 mm, ZS-221 white coating, carpet, 0.5 m sunshade width, and turning off windows (doors). The proposed retrofitting strategy can be promoted to a wide range of traditional rammed earth houses in the Lingnan region in China and holds a conspicuous energy-saving potential for the suburban and rural residential sectors in the region.