LCA is a tool which has been used for many years in industries such as chemicals and packaging and is now being extended to construction.
This study looks at the application of LCA to the use of different methods and materials in construction, including the use of steel frames. It takes the basic inputs of raw materials and resources required to support the process of construction and running operations and evaluates the outputs in terms of the products used: emissions to air such as carbon dioxide, sulphur dioxide and nitrogen oxide; emissions to water; and waste produced.
The study includes a comparative case study of two office blocks which showed that different framing systems have little or no bearing on energy use or CO2 emissions. It also demonstrated that operational rather than embodied energy is dominant. Five types of structural system and a range of service options from natural ventilation through various mechanical systems to full air-conditioning were investigated for both buildings. The complete life cycle energy use and CO2 emissions for all these alternative structures plus all the Heating, Ventilation and Air Conditioning ( HVAC ) options were considered.
The study concludes with an assessment of the operational efficiency of different types of ventilation ( air conditioning, mechanical ventilation, natural ventilation ) and the advantages of steel as a construction material.