Rising energy costs and increasing environmental concerns are catalysts for introducing sustainable design features in buildings. Incorporating sustainable design features in commercial buildings cannot be overstated because it could confer benefits to the investor (owners) and occupants. This study aims to develop a model that could aid in the prediction of operation and maintenance (O&M) costs from the knowledge of building-design variables. There is little evidence that design variables influence the O&M costs of buildings. Therefore, this study investigates the relationship between design variables and O&M costs in commercial buildings with the intent of developing a cost model for estimating O&M costs at the early design phase.
The study was approached quantitatively using a survey strategy. Data for the study were obtained from 30 randomly selected commercial buildings in the CBD in Colombo, Sri Lanka. Pareto's 80/20 rule, correlation and regression analysis were performed on the data to prove the statistical relationships between the buildings' O&M costs and their design variables.
The study found that 12 significant O&M costs elements contribute to about 82% of total O&M costs. Repairs and decoration had a strong correlation with building shape. Furthermore, the regression analysis found that O&M costs values were primarily dependent on the building size (the gross floor area and height of the buildings). The gross floor area and height handled over 73% of the variance in the O&M costs of commercial buildings in Sri Lanka.
These findings are a useful insight into the principles for design economies that could contribute to more sustainable commercial buildings.
