A novel holistic EPC related retrofit approach for residential apartment building renovation in Norway

This paper presents a novel Energy Performance Certification (EPC) related holistic building retrofit approach for a Norwegian apartment block built in 1980s. Based on the pre combination principles of “Fabric priority”, “Renewable in supplement”, “Avoid complicated installation”, 11 energy retrofit measures (ERMs) were defined and combined into 18 typical retrofit combination packages (COMBs). Targeted simulations with the aim to explore the interconnected and coupled impacts of selected ERMs are performed in a dynamic simulation tool IES Virtual Environment (VE). A novel Energy Limiting Difference (ELD) assessment factor has been defined, which only considers the difference between primary and renewable energy consumption in the extreme cold winter and hot summer months. The post retrofit EPC standard for each COMBs are then linked with these ELD assessment factors respectively. The relationship between ELD assessment factors and the relevant EPC grades for the 18 COMBs is plotted and verified against the obtained EPC results. Without performing the simulation for each month in conventional retrofit approaches, this approach leads to at least 78% reduced simulation efforts. This ELD-EPC related approach could therefore be used as useful guidelines for similar apartment building retrofits incorporating renewable energy measures in high density areas in the cold climate region