Assessment of Energy Consumption in Building Construction Phase: A Case of Sri Lanka

Buildings are responsible for one-third of the total energy consumption. Most of the researchers have given importance to energy consumption in the operational stage of the building. Even though the construction stage consumes an insignificant share of the total energy, further consideration must be given to this in order to reduce the cost of energy usage, because the cost incurred for fuels and electricity represents about 2.5% of total construction industry expenditures. Past studies revealed that early prediction of energy consumption of key construction activities, efficient utilization, and conservation of energy on-site can lead to 10–20% cost savings on energy usage. Thus, this research aimed to assess energy consumption during the construction phase through a case study analysis. Energy consumption data and other required data were collected from document reviews such as electricity bills, fuel records, and BOQs and further clarified through semi-structured interviews and site observations. The findings revealed that on average, electricity, diesel, and petrol consumed around 50–70, 20–30, and 10–15% of the total energy consumption, respectively, in the construction stage. The energy consumed for topsoil removal, excavation, backfilling, and concreting activities was 405 kJ/m2, 3100, 2174, and 42,000 kJ/m3, respectively. Further, energy consumed for demolition changes according to the purpose of work. This information on sources of energy and the respective construction activities recommends seeking alternative sources of energy and the consideration of energy-saving measures such as regular maintenance of the equipment, training the staff, and following the use of lean techniques to be used at the construction stage in order to reduce the cost.