In the Philippines, core-filled concrete hollow blocks (CHBs) are among the most common walling materials in residential design and construction. However, they contribute to internal overheating which can lead to occupant discomfort, poor thermal performance, and increased cooling demand. As ambient temperatures continue to rise due to global warming, there is a need for the Philippines to reconsider conventional building materials and explore alternatives that can support more sustainable thermal comfort in residential buildings.
Similarly, agricultural waste from local rice production remains a continuing concern. In a study conducted in one of the country’s major rice-producing provinces, it was found that a significant volume of rice waste is disposed of through dumping, among other disposal methods.
This study examined the effectiveness of rice husk ash (RHA) masonry units in enhancing the thermal performance of local residential designs compared with conventional CHBs. RHA masonry units are produced by partially incorporating RHA, which is derived from rice husk, a by-product of one of the Philippines’ leading agricultural crops. Recent literature suggests that these masonry units may provide favorable thermal performance due to the inherent properties of RHA. In addition, their use may provide a productive application for agricultural waste and help minimize rice waste disposal through dumping. However, further research is recommended to assess their feasibility for local production and implementation, as well as their structural performance, environmental impact, and overall sustainability.
The comparative assessment of these materials was conducted using the Passive House Planning Package (PHPP). While PHPP is primarily used in Passive House certification projects, it also serves as a reliable tool for evaluating a building’s thermal performance and energy demands based on the specifications of its envelope and systems.