RAFLESIA (Indonesian Solar Reflective House) as a Sustainable Solution for Uninhabitable Housing in Cirebon Regency

Abstract

The Urban Heat Island (UHI) effect in cities results from the reflection of solar radiation from roof and wall coverings, primarily in the form of short-wave radiation. Roof and wall materials experience the longest exposure to solar radiation on a building. Heat generated at the surface of these elements is transferred into the interior spaces. To reduce heat gain, materials with low albedo—often dark surfaces—and high solar reflectivity are needed. Indonesia’s geographical conditions, partly coastal, contribute to significant heat loads experienced by most of the population. This issue is further exacerbated by the fact that approximately 26.42 million low-income people have limited access to cooling systems, making them vulnerable to heat stress. One efficient solution is the Indonesian Solar Reflective House (RAFLESIA), which utilizes metal cladding for roofs and walls that provide a high solar reflective layer. This study aims to evaluate how RAFLESIA improves thermal comfort by lowering indoor temperatures and to assess the effectiveness and efficiency of new materials for sustainable improvements in uninhabitable housing. The methods employed include participatory observation, interviews, and literature reviews. The RAFLESIA building design is tailored to the needs and existing conditions of the houses. As a result, the program addresses the issue of uninhabitable housing and reduces indoor temperatures by an average of 3℃, as well as electricity consumption by up to 20%.