In high-performance buildings, energy storage is a key component in increasing self-consumption of onsite renewable energy, but is also responsible for extra embedded burdens. The main risk is not paying back these extra burdens through operational benefits during the use phase of the building. The aim of this study is to define, explore and propose a methodology for assessing the limits of the viability of energy storage systems when embedded in a building, utilising a set of indicators including greenhouse gas emissions, primary energy and costs. These values are therefore of importance when designing a building energy system integrating renewable energy source and energy storage. Beyond the results obtained for a case study in Switzerland, the study unveils different mechanisms according to the scheme of renewable energy exports. Results are greatly affected by the geographic context and demonstrate the necessity to implement harvesting systems providing low-impact renewable energy in buildings.