Defining a framework to apply retrofitting optimisation models for long-term and step-by-step renovation approaches

Abstract

The recast of Energy Performance of Buildings Directive (EPBD) 2018/844/EU introduced in the article 19a the possibility of building renovation passports which provide a long-term and step-by-step deep renovation roadmap for a specific building. Preliminary results showed that optimisation models for deep renovation of existing building almost exclusively optimise single stage retrofitting. Different from the single stage approach, in the step-by-step approach the retrofitting measures are not performed at the same time. In the present study, we aim to understand how the methodological approach of optimisation models for single stage retrofitting can be adapted to a step-by-step renovation concept. For this, first, the existing optimisation models were compared in terms of integration with external tools for energy demand calculation, definition of the renovation measures, objective function, and the question to which extent they consider long-term dynamic aspects of step-wise retrofitting optimisation over several years or even decades. Second, after identifying possible obstacles for adapting existing optimisation approaches towards step-by-step renovation, a framework for a step by step renovation optimisation model was outlined. The framework defines how the single stage retrofitting measures could be broken down in different renovation steps over a period of several years or even decades and which criteria should determine the time-wise prioritisation of the retrofitting measures. With this approach, we prepare the ground for the development of innovative tools, supporting the provision of individual renovation roadmaps. Next steps of the present study are testing and improving the outlined optimisation approach, as well as, extending the results to a building stock scale. By that, we aim to develop a method for analysing possible impacts of step-by-step renovation measures on achieving building stock’s decarbonisation targets.