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Abstract
Historically, clients have been interested in minimising initial construction costs. In the last few decades building users have begun to discover that the maintenance and operating costs impact significantly on Whole Life Costs (WLC) over the life of buildings. In this thesis, a generic comprehensive WLC data breakdown structure and Structured Framework for Estimation (SFE)of WLC for the building industry are presented. The WLC data breakdown structure and SFE of WLC identify all WLC elements, cost and other data, and information needed to estimate WLC throughout all project phases and stages. A WLC mathematical model is presented which allows the estimation and trade-off of WLC at the lowest level of detail (e.g. elements and/or components and resource level). A WLC implementation model is presented which embodies the "theory of significance" in order to simplify the procedure for estimation of WLC, focusing only on identified WLC significant elements thus reducing the effort involved in data collection and analysis. The WLC implementation model also embodies the application of Failure Mode and Effects Analysis (FMEA) and Reliability Centred Maintenance (RCM) techniques in order to identify the most applicable and cost effective maintenance tasks to minimise the WLC of building elements. WLC mathematical and implementation models are applied to three different types of projects (high school, housing scheme and prison) with the objective of demonstrating the minimisation of WLC and, at the same time, satisfying certain performance requirements. A detailed trade-off analysis is carried out at the element and component level and the lowest WLC alternatives are identified. It is found that a WLC saving can be achieved in the range from 6% to 29.2% per WLC significant element (e.g. windows, floor finishes etc.), depending on the functional area of the different types of analysed projects, as well as on the applied discount rate, economic life and service lives of the components. The WLC implementation model provides the guidelines for the implementation of WLC estimation and defines the way for the minimisation of WLC, satisfying the identified client's and certain performance requirements.