The BIQ Haus in Hamburg-Wilhelmsburg was the first building clad in living culture. 129 flat-panel photobioreactors — 2.5 m by 0.7 m, four glass layers, 24 litres of microalgae each — hang in white aluminium mullions across two faces of a grass-green rendered block, growing biomass and harvesting heat.

This system takes the facade literally. The painted wall is the ground, the panel array is the figure, and the culture is never one flat colour: it brightens where the medium is thin and backlit, collapses to near-black olive where it is dense or shaded, and reads cold blue-grey where a panel is idle and reflecting sky. Rigid grid, engineering type, liquid behind glass.