Many cities are striving to develop urban transformation strategies, in order to transit from traditional city to a sustainable city. Improving the energy efficiency of the existing buildings is the key to address climate change mitigation and adaptation. This paper considers different climate scenarios using different series of future climate in four different European cities, namely, Kiruna, Stockholm, Valencia and Madrid. The study adopts the TABULA database to get access to basic construction information. Energy simulation and data analysis using IDA ICE and MATLAB are performed. Based on climate change, an overall retrofitting plan was developed by combining energy-saving retrofit solutions. The results show that in Madrid and Valencia, future heating demand will decrease and cooling demand will increase. In Kiruna and Stockholm, with the increase of the insulation material, the heating demand of the house has decreased, but the cooling demand has shown a downward trend compared with the cases of Madrid and Valencia. The first reason is the introduction of hybrid cooling, and the second is that the average indoor temperature has been maintained at 21 degrees Celsius due to the low outdoor temperature in summer. The findings indicate that in Kiruna, Stockholm, and Madrid it is better to insulate façades to lower the heating demand in winter. In Valencia, it is possible to have relatively low heating and cooling demand without façades insulation as insulated façades require more cooling demand during summer.