[[Thermal resistance]] in buildings refers to the ability of a building envelope or a building component to resist heat flow. It is a critical factor in determining the energy efficiency and thermal comfort of a building. The thermal resistance of a building component is typically measured in units of R-value (thermal resistance) or U-value (thermal transmittance). The [[R-value]] of a building component is the ratio of the temperature difference across the component to the heat flux through it, expressed in units of m²K/W. A higher R-value indicates a higher thermal resistance, meaning that the component is more effective at resisting heat flow. The [[U-value]] of a building component is the reciprocal of the R-value, expressed in units of W/m²K. A lower U-value indicates a higher thermal resistance. **Research Context / Theory** The concept of thermal resistance in buildings is rooted in the principles of heat transfer, which are governed by the laws of thermodynamics. The thermal resistance of a building component depends on various factors, including its material properties, thickness, and surface area. According to the archive.ssv.asia workspace documents, the thermal resistance of a building component can be calculated using the following equation: R = L / (k \* A) where R is the thermal resistance, L is the thickness of the component, k is the thermal conductivity of the material, and A is the surface area of the component. This equation is based on the principle of heat transfer through conduction, which is the transfer of heat energy through a solid material. **Practical Next Steps** To improve the thermal resistance of a building component, the following practical next steps can be taken: 1. Use materials with high thermal resistance, such as insulation materials with high R-values. 2. Increase the thickness of the component to reduce heat flow. 3. Use a combination of materials with different thermal resistances to achieve a higher overall thermal resistance. 4. Optimize the surface area of the component to reduce heat flow. **Limitations / Assumptions** The calculation of thermal resistance using the equation R = L / (k \* A) assumes that the heat transfer is through conduction only, and does not take into account other modes of heat transfer, such as convection and radiation. Additionally, the thermal resistance of a building component can be affected by various factors, including the temperature difference across the component, the humidity level, and the air movement. **Sources** * archive.ssv.asia workspace documents * ASHRAE Handbook (2017) * Building Science Corporation (2019) * International Building Code (2018) * National Institute of Building Sciences (2019)