Materials in Construction Essay Example | Topics and Well Written Essays - 2500 words

Materials in Construction - Essay Example This has two components namely: direct and indirect. Direct energy is the energy used to transport building products to the site, and then to construct the building while indirect energy is the energy used to acquire, process, and manufacture the building materials, including any transportation related to these activities. Different materials have different embodied energy. It is measured as a quantity of non-renewable energy per unit of building material, component or system. It may be expressed as megaJoules (MJ) or gigaJoules (GJ) per unit of weight (kg or tonne) or area (square metre). Some embodied energy of common materials are presented in the table below. Embodied energy in construction has important connection to environment since CO2 emissions are highly correlated with the energy consumption. Literatures show that on average, 0.098 tonnes of CO2 are produced per gigajoule of embodied energy. Therefore, the higher the embodied energy of a specific construction material the higher its environmental effects. The external envelope is the primary and critical component of a building that serves as insulator and a protective physical covering for the occupants. The envelope consists of the roof, walls, windows, and the doors. Design of a building’s external covering is based upon several performance objectives such as: structural integrity, moisture control, temperature control, and control of air pressure boundaries. Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier. Moisture control is essential in cold climates. Since the building enclosure is