Bio Facades (Algae): A Case Study: BIQ Building

Name of case study

The Bio Intelligent Quotient (B.I.Q.) Building: SolarLeaf


  • Hamburg
  • Germany




  • Urban
  • Landscape

Area / size

129 bio-facade panels, making up 200m2 of integrated photo-bioreactors. It is a 4 storey apartment building.

NbS employed

Bio Facades (Algae)

Type of NbS

Created or constructed living ecosystems


Research and development by Colt International based on a bio-reactor concept developed by SSC Ltd and design work led by the international design consultant and engineering firm, ARUP. 


The German Government’s “ZukunftBau” research initiative.


  • Graz
  • Austria



The B.I.Q House; Image source:
Climate change benefits
  • Increased temperatures
  • Urban heat island effect

Renewable energy and carbon reduction: The algae creates heat, creating a carbon-free heating and hot water source, that uses no additional land use. The closed loop system creates carbon reduction on three levels: direct carbon sequestration from the air (used to feed the algae), absorption of carbon (by the algae), and a reduction in energy use.  

Read More
Societal / socio-cultural benefits
  • Energy security

Bio-facades can be retrofitted onto existing buildings and implemented on new buildings to create healthier buildings generating their own renewable, carbon-neutral energy. If buildings and cities are healthier, so too are people.  

Read More
Ecological benefits
  • Education and knowledge
  • Production of fuel / energy
  • Nutrient cycling

Algae is an almost unlimited source of energy and food, and absorbs CO2 at a rapid rate. Algae grown from bio-facades have the potential to be converted into renewable fuel stocks such as biomass or biofuel (Kim, 2013).  

Read More

Summary of case study

The BIQ house in Hamburg is an apartment building with 4 floors and 15 units. The facade system was developed by Strategic Science Consult (SSC), a bioengineering company; Colt International, a global supplier of climate control systems; and Arup, a collective of designers, experts and advisors. The building itself was designed by SPLITTERWERK Architects of Graz in Austria. 

The facade system is called SolarLeaf and is fully integrated into the building. In total, 129 bioreactors measuring 2.5m x 0.7m have been installed on the south-west and south-east faces of the four-storey residential building to form a secondary façade (Arup, 2013). 

The bioreactors are glass panels filled with nutrient-rich fluid and microalgae. There are four glass layers – two inner panes housing 24 litres of liquid. Then insulating, argon-filled cavities minimise heat loss. The two outer panels are made up of anti-reflective glass and decorative glass features respectively. 

Each bioreactor receives compressed air. The gas creates large air bubbles and generates an upstream water flow. This movement stimulates the algae to absorb CO2 and daylight. This process creates energy and heat, and a biomass byproduct. The system provides one-third of the total heat demand of the residents and can be operated all year round. 


<< bio-facades