Whilst new nearly Zero Energy (nZE) concepts have been the first priority in the previous decade, in more recent years it has become widely acknowledged that renovating dwellings will have a large impact on the energy use in buildings. Using a simplified calculation method, this paper illustrates the high-energy consumption in several building types within the housing stock in Bologna. Among these, a specific building has been selected as the worst-case for an in-depth investigation. For this building the paper analyses a large set of possible scenarios for renovation-from the more standard operations up to higher levels of facade components' transformation- as technically feasible solutions to achieve a nearly Zero Energy Building (nZEB). By discussing the economic/energy impact of each scenario, this paper aims at contributing to the debate on deep-versus-shallow renovation in existing buildings. In particular, it attempts at answering the following important research issues: whether the technical feasibility is associated to the economic feasibility in the retrofitting towards nZEBs; to what extent deep renovation and high transformation of buildings is competitive with respect to shallow retrofit; whether non-energy related factors can be considered to properly assess the economic competitiveness. Energy and economic benefits are the main renovation's objectives in building renovation; nonetheless, non-energy related aspects are also helpful to expand the feasibility of nZEBs retrofit in the current building practises. (C) 2017 Elsevier B.V. All rights reserved.