For centuries, new buildings have been built on the ruins and foundations of previous works. Isbuilding not far from re-building? The presence of the past is project forming. Architecture is aboutcarrying forward what has preceded us, providing a more advanced version of how we found it. Weare not interested in embalming the past. We prefer to recognize its ability to accept thetransformation without denying it. As personal experience I bring to edA the reconstruction of theDom Römer quarter in Frankfurt. The case history is dedicated to the second reconstruction of thesite, destroyed by bombs and by the first afterwar reconstruction. M34 is a passive house featured forhigh sustainable performances (as the old/new quarter all around - project with Anna Worzewski,Ilaria Corrocher, Valentina Fantin, Serena Acciai - Monumental Pergola also with PAS Jourdan &Müller + Steinhauser).