3. Microalgae biofacades

Microalgae biofacades consist of PBRs installed vertically on the facade of a building. This inherently offers several technical advantages (i.e. the architectural appeal will not be discussed here, although it may also come into play):

• a reduction in competition with agricultural land and land use in general,

• pooling of construction materials for microalgae cultivation systems with those used in building construction,

• the possibility of establishing material and/or energy exchange loops between the building and microalgae (i.e., symbiosis) to reduce the environmental impact of these two systems (Figure 1 ).