The refurbishment of the building stock is one of the key tasks for reducing future environmental emissions. The environmental emissions are mostly assessed with the Life Cycle Assessment (LCA) method, where the refurbishment is usually considered as the beginning of the new life cycle, and all the impacts associated with the life cycle before the refurbishment are neglected. In order to overcome this inconsistency, in the PhD study an advanced LCA methodology was developed that allocates the impacts between the life cycle before and after the refurbishment, and assures the use of time-corresponding data. In this sense, the neglecting of the environmental impacts before the refurbishment, as well as the double-counting, is eliminated.
The developed methodology consists of two sub-methodologies. The first sub-methodology is used for remodelling the input data, in order to make them time-corresponding. The second sub-methodology enables the allocation of environmental impacts before and after a refurbishment and calculation of the residual value of materials. Both sub-methodologies can be used also individually. Additionally, a methodology for the comparison of the environmental impacts of refurbishment measures that also includes operational EI was developed.
The thesis proved that the use of time-appropriate data for the analysis of environmental impacts is extremely important. For building refurbishment, it is also crucial that environmental impacts are allocated to the life cycle before and after renovation, especially when materials are recycled or reused. The comparative methodology for the refurbishment measures indicated that in Central Europe the position of the thermal insulation layer does not significantly affect the heat storage capacity of buildings, and that the environmental payback period for the façade refurbishment is mainly dependent on the environmental impacts of the thermal insulation itself.
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