the life cycle performance of sustainable renovation concepts

4.2.2 WHATThe model that is presented in figure 28 can be used to determine the performance ofsustainable renovation concepts on the basis of a life cycle approach. The life cycleapproach refers to a cradle-to-cradle consideration of the performance on the definedsustainability aspects for renovation concepts. Hereby, the cradle-to-cradle approachrefers to the potential advantages of reuse and up-cycling of materials and components.Therefore, the model is defined as a “life cycle performance evaluation model” forsustainable renovation concepts.The “life cycle performance” is composed by a renovation concept‟s life cycle:- performance on environmental aspects- performance on economic aspects, which consists of:• performance on life cycle costs• performance on life cycle yields- performance on quality aspects- energy performanceApplication of the model results in a comparison of the life cycle performance ofrenovation alternatives for a specific project. The model draws a distinction betweenprojects, because every renovation project is unique. As a result, the performance of arenovation concept, and thereby its feasibility and desirability can differ per project.The life cycle performance evaluation model integrates five main performance aspectsand boundary conditions. Figure 29 presents these five main aspects and the boundaryconditions. Appendix L shows a complete breakdown structure of the model and itsunderlying factors.BoundaryconditionsBoundaryfactorsLife CyclePerformanceLife CycleCostsLife CycleYieldsLife CycleEnvironmentalImpactQualityEnergyPerformanceCoefficientMainfactorsFIGURE 29 - MODEL ASPECTS4.2.3 WHYThis paragraph explains the „why‟ questions that are stated in figure 27. First, an answeris provided on the question: “Why is the model developed?”First, the evaluation of existing sustainability assessment tools in the Netherlands(appendix M) points out that the current existing models are mainly useful to determinethe sustainability of new development projects. As a result, these models are not- or lessuseful for the evaluation of sustainable renovation concepts.Secondly, the existing tools are incomplete. The existing models only focus on one or afew aspects that are relevant for the performance of sustainable renovation concepts.Thus, none of the current models provides a comprising view on the performance of asustainable renovation concept.48