There are certain advantages in applying an airlift photobioreactor (PBR) intended for microalgae culture to a building façade, such as making use of the solar illuminated surfaces and the possibility of chemical recycling through photosynthetic growth (utilizing the carbon dioxide emissions from boiler combustion, for example). This study concerns the development of a thermal model for integral building-façade photobioreactors which can predict dynamic changes in the temperature of the culture medium in response to changes in meteorological conditions, taking into account the thermal interchange with the host building. The proposed model was experimentally validated with data obtained in outdoor conditions, using a pilot-scale system (SymBiO2-Box) located in Saint-Nazaire (France), and subsequently used to set up numerical simulations and optimization studies to develop control strategies for efficient thermal regulation of the PBR with optimal energy consumption. The advantage of using an active passageway between the façade and PBRs was investigated in particular.