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The EC funded 7th framework project CILECCTA sets out todevelop a LCCA (Life Cycle Cost and Analysis) tool supporting the determinationand costing of sustainable project alternatives. It proposes two main advancesover current practice in LCC and LCA: first it explicitly takes account offuture uncertainty during the project life or study period, and second itintegrates LCC and LCA in a single evaluation tool.
It is impossible to make design decisions that guarantee the optimal life cycle performance of buildings and constructed assets, because long-term performance is subject to the uncertain future evolution of factorssuch as the rate of climate change, the prices of fossil fuels and renewable technologies, the rate of decarbonisation of electricity, etc. Therefore it isa good idea to develop design strategies incorporating flexibility, enabling efficient adaptation in response to unfolding events.
It is proposed that flexibility can be achieved by providing 'lifecycle options' for upgrading or switching elements of a building orconstructed asset. These options are identified at the time of design and are exercised during the service life if it is advantageous to do so, otherwise they remain unexercised. At the time of design it is uncertain when or whether the options will be exercised.
This paper sets out the first practical test of the LCCA methodology developed in the CLIECCTA project, illustrated with an example concerning the design decision about the level of insulation in a building. Alternative designs are analysed with respect to both cost and environmental impact, identifying the most efficient and sustainable design strategy.
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