In the optic of providing guidelines for the optimal integration of renewable energy in a connected multi-energy context, this report presents EPFL - IPESE and EPFL - PV-lab’s common work on the initial assessment of Romande Energie (RE) demonstration site. To do so, a building and electrical grid-centered approach was selected, capitalizing on the laboratories research knowledge [MP5, MP6] and on existing databases existing for the built and electrical environment. In a first phase (section 2), a contextualization of the demonstrator is done by introducing the challenges to be tackled within the Swiss household sector for the energy transition. The second phase of the deliverable (section 3) focuses on gathering and compiling information on the RE demonstration site from various databases. The data heterogeneity is tackled by the development of a tool allowing to automatize this approach and therefore provide a basis for a generalization of the approach at the Swiss scale. Based on these informations, the third phase (section 4) provides an assessment of the demonstration site according to various factors, such as: diversity, impact and potential, on three different axis: buildings, thermal energy and electricity. Indicators computed on actual data are defined, such as the diversity indicator, to allow performance quantification. Based on these indicators, the fourth phase (section 5) aims at selecting subsystems as well as defining scenarios that will serve as basis for the upcoming optimization. Using a weighted decision matrix, a selection of subsystems bounded by the corresponding low-voltage grid are compared, and the most promising technologies identified for these subsystems are chosen in order to generate scenarios. During the fifth phase (section 6) and for each of these selected subsystems, an optimization combined with an extrapolation is performed in order to assess the potential bottleneck of renewable energy integration. Finally, the sixth phase (section 7) provides insight into the future developments of the proposed methodology in the optic of providing actual guidelines for the planning of multi-energy systems.