Thermal Insulation Performance Standards for Prefabricated Houses

There are no nationally unified specific values for the thermal insulation performance standards of prefabricated houses, but relevant building codes and standards have put forward requirements from different aspects.

I. Building Code Requirements The "Residential Building Code" requires that residential buildings should meet corresponding thermal insulation indicators to reduce energy consumption and indoor temperature fluctuations. This means that when designing and constructing prefabricated houses, this principle should be followed. Through reasonable architectural design and material selection, good thermal insulation effects can be achieved, keeping the indoor temperature relatively stable and reducing energy losses caused by temperature changes, such as reducing the frequency of use and energy consumption of air conditioners, heating equipment, etc. The "General Rules for Civil Building Design" stipulates that buildings should adapt to the climatic conditions of the area where they are located and take effective thermal insulation measures, such as setting up thermal insulation layers and using thermal insulation materials. There are significant climatic differences in different regions, and prefabricated houses need to choose appropriate thermal insulation methods according to local actual conditions. For example, in hot regions, more efficient thermal insulation materials and more complete thermal insulation layer designs may be required to block external heat from entering the interior.

II. Material-Related Standards For expanded polystyrene (EPS) foam boards commonly used as thermal insulation materials in rural assembled prefabricated houses, referring to relevant building energy efficiency standards, the thermal conductivity of EPS is generally around 0.038 W/(m·K). Thermal conductivity is an important indicator for measuring the thermal insulation performance of materials. The lower the value, the better the thermal insulation effect. The relatively low thermal conductivity of EPS enables it to effectively prevent heat transfer and reduce the exchange of heat between the interior and exterior. In terms of prefabricated thermal insulation panels, according to industry standards, they should comply with the relevant requirements of GB/T 25975 - 2018 "Thermal Insulation Products for Buildings". When selecting prefabricated thermal insulation panels, key parameters such as thermal conductivity need to be considered. Generally, the thermal conductivity should be ≤ 0.045 W/(m·K) to ensure that the thermal insulation panels have good thermal insulation performance.

III. Thermal Insulation Quantity Evaluation Standards The thermal insulation performance of houses can also be evaluated from the perspective of thermal insulation quantity. The thermal insulation quantity of residential buildings should generally be no less than 2.5 watts per square meter. Building sound and thermal insulation standards can be divided into three levels: Level 1 requires a thermal insulation quantity of ≥ 3.0 watts per square meter, Level 2 requires a thermal insulation quantity of ≥ 2.5 watts per square meter, and Level 3 requires a thermal insulation quantity of ≥ 2.0 watts per square meter. These different levels of thermal insulation quantity standards provide clear quantitative bases for evaluating the thermal insulation performance of prefabricated houses.