Selection of External Wall Material by LCC Technique for Ofice-cum-Commercial Building in the Eastern Province of Saudi Arabia

Abstract: The building construction sector in the Kingdom of Saudi Arabia (KSA) is the largest and fastest in the GCC states. Building Envelope has a major role in deciding the cost and energy performance of a building. As far as KSA is concerned, application of life cycle costing (LCC) technique, which performs the cradle-to-grave assessment of a building, for selecting building materials and structures is rarely reported in the literature. The present study has focused on selecting external wall material based on life cycle cost (LCC), at the design stage. A typical office-cum-commercial high-rise building situated in Al-Khobar, Eastern Province of KSA, has been selected for the study. The LCC of the building was evaluated by employing 14 commercially available external wall materials, by considering a life span of 20 years. The building was modelled by using Autodesk REVIT (2015) and the energy consumption of the building was calculated by performing energy simulation by the ECOTECT (2011) software. The uncertainty and sensitivity analyses were performed by using Monte Carlo simulation technique, by employing Crystal Ball Software. The results indicate that the external wall material adopted for the building is not recommendable in terms of both initial cost and LCC. The best material options identified share common features such as 12.5mm inner layer of Gypsum Board, 150 mm Concrete Block, 70 mm Polystyrene or Polyurethane insulation layer and an outside layer of 12 mm cement plaster. These options offer 7% saving in LCC compared to the default option.Keywords: External wall; Life cycle cost; Commercial building; Initial cost; energy consumption; Monte Carlo simulation.