Based on the audits realised on buildings by the UNIGE-CUEPE in 2007 [2], [3], the present work studies the conditions of the integration of the energy conversion system and of the building refurbishment options to fit with the GLN network and to prepare the data for integration using the tools developped in the frame of GE WP1.1. The method developed for designing and optimising the large scale integration through low temperature networks of district area is based on the data generated using the method described in [1]. When existing buildings are considered, the data obtained by extrapolation of statistical measures may be replaced by the data measured in the building. In order to maximise the efficiency of the building integratiojn, it is important to realise the study of the integration of existing buildings, considering on the one hand the results of the measurement done in the building and on the other hand the possible options related to the building refurbishment and the reuse of existing equipment. This report explains the approach developed to study the audited buildings inorder to generate the data needed to apply the so called DESD(OP)2 program (``District Energy System Design and OPeration Optimisation'') which has been developped in the frame of the WP1.1. The measured information from the audits carried out by the UNIGE-CUEPE are needed to set the problem with the different building signatures, annual energy quantities and the corresponding temperature levels. The climatisation distribution loops only have been audited, no data was available from these reports regarding heating and sanitary hot water values and therefore for these data the statistical values will be used.