What is the Solar Reflectance Index (SRI) used to measure?

The Solar Reflectance Index (SRI) is specifically designed to measure a roof's ability to reject solar heat. It combines two important factors: solar reflectance and thermal emittance. A higher SRI indicates that a roof surface reflects more solar energy and efficiently emits the heat it absorbs, thereby reducing the heat island effect and improving energy efficiency in buildings.

This index is particularly useful in evaluating roofing materials and designs, guiding decisions to help minimize cooling loads and energy consumption in response to solar radiation. Understanding the SRI is essential for architects and designers focusing on sustainable building practices and optimizing thermal performance, especially in hot climates.