The main purpose of the research is to suggest qualitative and efficient integrated solutions of solar energy into existing buildings in a delicate balance between energy production and respect of the building quality and its context. Solar capture is integrated into the building envelope according to harmonious composition respecting the global architectural logic. Calculations show that existing buildings have significant potential for solar integration on both roofs and facades. The research raises many questions about the way we apply solar panels on the different parts of a building and encourages developments of products as photovoltaic and thermal panels towards sustainable buildings.