A simplified model for predicting running cost of office buildings in Sri Lanka

Life cycle costing (LCC) is a technique used for assessing and predicting the cost performance of buildings and facility assets. Despite the importance of using LCC in buildings, its application in the building sector seems limited over the time due to the practitioners' imperfect understanding of the LCC’s merits, lack of reliable and consistent data, lack of incentives to use LCC, and the limited experience in using LCC calculations. In the Sri Lankan context there is no properly defined operation and maintenance cost sources which can be used as a cross-reference to the LCC in commercial buildings. This research develops a model for forecasting life cycle running costs of commercial buildings.The research was undertaken using a qualitative approach with multiple case study design. The running costs data were extracted from documents referring to cost data of total number of eight high-rise commercial buildings. A regression analysis was used for developing the cost model.The analysis of running costs indicate that on average the utility and administrative cost of commercial buildings ranges between 29% - 38% of total running costs, while taxes and subsidies vary between 6% - 16%. On average the cost of cleaning contributes to 10% of total running costs while building services maintenance and general maintenance contributes equally 6-9%. The insurance and external works range less than 1% in the commercial buildings in Sri Lanka.The developed model shows that the average floor area and the number of floors account for over 98% of the accuracy of the cost estimation for commercial buildings in Sri Lanka. The research therefore considers that the model could provide quick and accurate cost estimation for the life cycle running costs at the acquisition stage of commercial buildings.