The first zero net energy housing project in the Nordic countries

11 November 2014
Ramboll has designed the Nordic countries’ first housing project consisting of zero net energy buildings in Arendal.
Aerial view of the Skarpnes buildings

Aerial view of the Skarpnes buildings


Ole Bachke

Civil Architect
T: +47 402 08 768

The Skarpnes buildings lie on a sunny hill on the west side of Nidelva in Arendal and will be the largest zero net energy housing project in the Nordic countries. Skanska is the owner, developer and contractor on the ground-breaking Norwegian project.

The researchers are tasked with analysing how the power grid and the houses themselves are affected when the zero net energy houses are constructed. This is done through the research project Smart Village Skarpnes and EBLE (Evaluation of Buildings with Low Energy-consumption).

Integrated solar panels

Skanska has begun the construction of 17 single-detached dwelling and the aim is to finish them within two years. In addition to these, construction of 20 flats and three terraced houses will begin in the spring of 2015. Ramboll is the architect of the housing project.

- This project has been both exciting and educational. The challenges of the project have forced us to think out of the box, Ole Bachke, project manager at Ramboll, explains.

- We have had to modify several technical features such as solar panels and solar cells integrated in the roof and façade of the buildings. On top of this, we are dealing with very thick walls, he elaborates.

    In order to meet the requirements the houses’ window area will also have to be kept down. But Ole Bachke points out that in spite of this, the daylight factor of the homes is excellent.

    Cost-effective zero net energy solution

    The buildings are equipped with existing technology like solar panels, solar cells and ground source heat pumps, but everything has had to be modified.

    - The new challenge is that these technical features will have to be combined optimally and modified to meet the specific energy needs of the homes. The question has been how to do so cost-effectively, Cato Dippner, sales manager at Skanska, explains.

      It has been an exciting challenge for the architects to come up with aesthetically pleasing solutions that incorporate all the technical features.

      - Skanska would like the buildings to have a modern look, while at the same time matching the old wooden houses in the area around Nidelva. Because of this, the new buildings will be built with gabled roofs. This has been especially challenging to achieve with all the features that have had to be integrated in the façade, Ole Bachke explains.

        Smartphone and tablet control temperature and air conditioning

        The technical challenges will, however, not be noticed by the occupants.

        - The homes come with an intuitive control panel that regulates areas like temperature and air conditioning and which can be used remotely via smartphone or tablet, a feature most of us are comfortable with already. The technical maintenance is very straightforward, Dippner explains.

          Skanska plans to train the buyers of the homes and will be offering to service the homes for three years after the initial takeover.

          About the Skarpnes housing project

          Zero net energy houses have solar panels on the roof. Surplus electricity produced in the hot season will be delivered through the power grid to Agder Energy and will be returned during the cold season.

          Ground source heat pumps will be drilled for each single-detached dwelling. The apartments will share pumps. The ground source heat pumps will have a constant temperature throughout the year (7-8 degrees Celsius) and will be used for both heating of building and water as well as for cooling the building during the hot season.

          Wall-mounted solar cells capture the heat from the sun and supply the buildings with hot water for heating and domestic use. Surplus heat will be stored in the ground source heating pump during the hot season and will be able to be utilised during the cold season, when the ground source heat pump is supplying some or all of the building’s heating.

          Balanced air conditioning with heat accumulation provides a pleasant indoor climate. The air conditioning is connected to the ground source heat pump and utilises the constant temperature in the ground to provide passive heating and cooling.

          Ramboll Group A/S

          Ramboll Group A/S
          Hannemanns Allé 53
          DK-2300 Copenhagen S
          Tel:+45 5161 1000
          Fax:+45 5161 1001


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