Which type of building material typically has the lowest embodied energy?

Wood is known to have the lowest embodied energy among the options given. Embodied energy refers to the total amount of energy required to extract, process, manufacture, transport, and install a building material. Wood, being a natural product, typically requires less energy to obtain and process compared to more industrialized materials like steel or plastic. The lifecycle of wood includes the energy used in the growth of the trees themselves, which can also be considered a renewable energy source as trees absorb carbon dioxide and produce oxygen during their growth.

In contrast, steel is produced through energy-intensive processes that involve mining, refining, and machining raw materials. The production of plastic also entails significant energy consumption for the extraction of fossil fuels and the processing in factories. Gypsum board, while less energy-intensive than steel or plastic, still requires processing and transportation that contributes to its embodied energy. Consequently, wood stands out as the material with the least embodied energy, making it a more sustainable choice in many cases.