Photo: Christensen & Co Architects A/S

Green Lighthouse: a beacon for low-energy buildings 

A futuristic round building in Copenhagen points the way for climate-friendly construction in the future. COWI provided engineering expertise and developed the building's energy plan.

A low-energy, CO2 neutral building called Green Lighthouse will house lectures, meetings and administration offices for the University of Copenhagen from spring 2009.

From its conception, Green Lighthouse was designed to use the least possible amount of energy for heating and ventilation and to produce electricity on its own for lighting.

Solar cells, sun collectors, natural ventilation and shading reduce the need for cooling. High glass windows and overhead skylights provide natural lighting. In addition, the house’s circular floor plan creates a smaller facade, reducing the need for central heating.

Close co-operation
The project is the result of close co-operation between several organisations including the Danish University and Property Agency, the city of Copenhagen and skylight manufacturer Velux. COWI was responsible for providing engineering expertise and for the development of the energy plan.

Photo: Christensen & Co Architects A/S

Green Lighthouse's round form creates a smaller surface area and lowers heating costs.



Demonstration modelSajet Mahmudovski, an engineer in the Danish University and Property Agency, explains that Green Lighthouse was envisioned as a model for how to build a self-sustaining commercial building with low energy consumption and the least amount of CO2 emissions.

“At the same time, we didn’t want to compromise either the architecture or the technical solutions such as how to secure adequate lighting and create a pleasant indoor climate,” says Mahmudovski. The house is conceived as a demonstration model for the UN climate conference, COP15, held in Copenhagen in December 2009, he adds.

More low energy housesThe Green Lighthouse will hopefully inspire energy efficient buildings in the future, says Michael Nielsen, an R&D Manager in COWI.

"Green Lighthouse is one of the first commercial buildings in Denmark which will represent a trademark for how you can build CO2 neutral buildings for a reasonable sum. I think that the building will help to generate demand for new, energy-conservation products for windows, sun collectors and heat pumps.”

Reto M. Hummelshøj, COWI, who helped to develop the energy plan, agrees.

“The project provides important information about how these systems can be integrated in the best possible way. That will lead to lower prices and the creation of more low energy houses.”

 

By Christina Tækker & Kathrine Schmeichel, cht@cowi.dk Published: 29.08.2008

Energy efficient solutions 

A number of energy saving features help to make Green Lighthouse self-sustainable.

Insulation is one of them. To maintain energy most optimally, low-energy windows have been mounted and the walls have been filled with 400mm of insulation, which is double the normal size.

Phase change material which consists of tiny pieces of wax fused in plaster is also used to improve the structure’s ability to absorb and release energy. The phase change material absorbs heat when the room temperature is high and releases it again when the temperature falls. In this way, energy consumption for heating and cooling is reduced.

Facts:

  • Area: 950m2
  • CO2 impact: 0
  • Developer: Danish University and Property Agency
  • Contractor: Hellerup Byg A/S
  • Engineering: COWI A/S