Green lighthouse

"One experiment is worth more than 1000 expert views"
Villum Kann Rasmussen

Therefore we are building real houses and trying things in practice. The purpose is to develop new knowledge about energy efficiency, comfort and aesthetics of future houses.

CO2 emissions shall be reduced

Scientists have confirmed that in 40 minutes, there is enough sun energy on the surface of the earth to support the world’s energy use for a whole year; good information in a time where climate changes are developing faster than previously expected. This requires that we are able to harvest the sun - and on a far greater scale develop and make use of new technologies. The way we build and live has a large meaning for saving the environment in our everyday lives. Energy use for construction and operation of buildings in the West makes up about 40% of the total energy use - energy that is primarily based on coal and in that way is connected to high CO2 emissions. There is a large challenge in developing the future building structure in such a way that it optimizes the use of sun energy and decreases the CO2 emissions.

Active building

An Active building is a vision of creating balance and unity through buildings that:

  • produce more energy than they consume
  • have a healthy indoor climate
  • interact with their environment 

ENERGY: An Active building is CO2-neutral. By using renewable energy sources it has an exceptionally low level of energy consumption and produces more energy than it consumes.

INDOOR CLIMATE: An Active building has a healthy and comfortable indoor climate, allowing people to express themselves and live their lives in comfort.

ENVIRONMENT: An Active building is designed, situated and constructed to interact with its surroundings.

VKR Holding has initiated the construction of eight demonstration houses in a number of European countries. Green Lighthouse is the second example of an Active building in Denmark.

Energy + good architecture

Green Lighthouse is a building where, based on a holistic approach, is a balance between architecture, light, a healthy indoor environment and an extremely low energy consumptionGreen Lighthouse is a building where, based on a holistic approach, is a balance between architecture, light, a healthy indoor environment and an extremely low energy consumption. Light is the central design element in Green Lighthouse. The building is organised based on the changing nature of light, both during the day and year and in relation to changing weather conditions.

New centre for science

Green Lighthouse acts as a centre of life at Nørre Campus, which is part of the University Park in Copenhagen. The building is 950 m² on three floors and is free standing with direct access from several directions in the park. With its round shape and green covering it will act as a strong visual landmark for the campus. In the building there are meeting facilities, student services and a faculty lounge.

New centre of the sun

The circular shape reflects the movement of the sun over the arc of the sky and the moveable sun protection will create a wave of different light through the different work areas during the day so they are always ensured plenty of light and at the same time the maximum visibility to its surroundings.

Daylight Factor

  • Minimum 3% near the office work areas
  • and 9% in the lounge

Energy concept

The roof is tilted to the south to take advantage of the sun as a major source of energy for operating the house.The purpose of the energy concept in Green Lighthouse is to make the building CO2 neutral. The roof is tilted to the south to take advantage of the sun as a major source of energy for operating the house. The energy concept is very new and consists of a combination of district heating, solar cells, solar heating and cooling and seasonal storage, which ensures the optimum use of renewable energy: for example, using solar energy for both cooling of the building in summer and to improve the efficiency of the heat pump in winter.


The proportion between windows and the facade is carefully adapted so that the building does not consume more energy for heating than necessary. The variation of the intensity of the sun is integrated throughout the energy system of the house. In the summer the excess solar power is stored into a warehouse under the house, which can then be used when the strength of the sun decreases.

Energy consumption in Green Lighthouse is calculated to be 30 kWh/m²/year which respectively:

  • 35% comes from 30,8 m2 solar collectors on the roof and storing solar heat in the earth (geo-thermal heat) through a heat pump.
  • 65% environmentally friendly heating with a share of renewable energy of about 35%.
  • The heat pump increases the utilisation of the district heating by about 30%. 


76 m² of solar cells on the roof will contribute to the electricity used for lighting, ventilation and pumps. The electric-based lighting in the house is LED with long life and extremely low energy consumption and all lighting is controlled by motion sensors that switch off the lights when leaving the room.

Ventilation and cooling

To minimise the energy consumption of the building, natural ventilation is used, which in winter is supplemented by mechanical ventilation. Window openings facing to the south, east and west are equipped with moveable sun screens either as a blind built into the wall above the window or as a screen mounted directly on the window. The screens give the possibility to shield the building from excess temperatures while daylight is let into the building. Blinds are also used for reflection of sunlight deep into the house, which reduces the need for electricity for lighting.


Unlike traditional constructions, which usually have heavy exterior walls and lightweight interior walls, the Green Lighthouse is built with lightweight and optimal thermally-insulated façade walls. The stabilising heavy concrete construction is moved a little into the house. The façade walls consist of 300 mm Rockwool framed in wood panels followed by a vapour barrier with 150 mm Rockwool sealed with 15 mm high-insulating plasterboard.


The active window of the future

VELFAC Innovation Centre has developed Helo, an energy+ window that supplies the buildings with more heat than is lost and that complies with the strict energy requirements of the future for both new buildings and renovations. VELFAC Helo is the window concept of the future where unique insulation properties are compatible with strength, durability, surface finish and design. The window contributes positively to the energy balance with regular 2- and 3- layer glass. VELFAC Helo supports both the low-energy house concept by using under 15 kWh/m² and the active house concept where the house shall produce more energy than it uses.

The frame and sash of the window are made of a revolutionary new material - Helo-Fibre that consists of PUR (polyurethane) strengthened with thin glass threads. VELFAC Innovation Centre tested initially more than 200 materials but did not find a material that was capable of combining the required characteristics. Therefore VELFAC developed Helo-Fibre in conjunction with leading material suppliers in Europe and North America. The material combines for the first time, unique insulation ability with strength, durability and surface finish.

Helo-Fibre is not only particularly suitable for the production of weather resistant low energy windows in high quality; the material is distinguished by the ability to be produced with a uniform beautiful surface. On the basis of its strength the material can be used in a very slim construction and in very large sizes. This gives the possibility to develop unique high-quality windows in a beautiful design with a large unhindered daylight intake. In 2010 VELFAC Helo will be offered for sale for specially chosen low energy buildings.

VELFAC doors

In addition to VELFAC Helo windows, VELFAC doors are also present in Green Lighthouse:

  • VELFAC 600 flush doors in wood / aluminum are used as emergency exit doors. The doors are supplied with an electromagnetic lock box which ensures limited, controlled access. The inner grip always activates the latch and acts in this way as an emergency exit. VELFAC 600 doors are available as both glazed and flush doors. The doors can be delivered as single or double leaf, single leaf with fixed side light or fire door.
  • VELFAC 500 doors in aluminum are used at the entrance for wheelchair users. The door is fitted with electromagnetic lock box and a motion sensor that automatically opens the door when a wheelchair user is approaching. VELFAC 500 doors can be delivered as single or double leaf, either inward og outward opening, and can be divided by glazing bars in one or more fields. 

Both VELFAC 500 and VELFAC 600 front doors can be placed together with VELFAC Helo, VELFAC 200i and VELFAC 400i side and top lights.