The 200 m2 modern and very comfortable house, was created in a cooperation between SIB (the local Construction Company), Grontmij (the Consulting Engineers), ProjectZero, SE (the regional Utility Company) and Danfoss Company. The house has a positive annual energy costs and sells the excess power to the national grid at the market price – the same price the consumers pay when they buy the power from the grid. The meter simply runs backwards. The concept of the ZERO+ House was proved its first year of operation: the house produced more energy than the family consumed.

The success of the house is based on a combination of energy efficient insulation, ventilation, passive solar heat, geothermal heat pump, photovoltaic and an ultramodern energy management system constantly monitors and optimizes the use of energy.

The energy consumption of the house was in 2009 and 2010 (the first 12 months) 5.133 kWh – including heating, cooking and all domestic appliances – out of which 2.890 kWh were used for lighting, ventilation, dishwashing, tumble-drying etc. During the same year the 42 m2 solar panels produced 5.160 kWh – a surplus of 27 kWh . The house was built in 2009. Since that time the cost of PV-technology has decreased by app. 20% per year and will continue to decrease. Grid parity has been achieved in Denmark for private homes and investments in PV. Energy efficient house construction is therefore not only good for the climate but also for the household economy. The ZERO+ House has not only inspired the development of the GEHRY Harbour project to be ZERO+, but the Danish Building Code for 2020 will also be based on the same passive house construction with a renewable energy production.

Objectives and beneficiaries

In 2009 Sonderborg became the first city in Denmark where Denmarks first ZERO+ house was build. The formal name of the house is the SIB ZERO+ House and it produces more energy than its family consumes in their everyday life.

Strong points of the practice

The program is focused on the EU energy label and qualified ways to improve the individual houses current energy standards. The ZEROhome program is supported by national funds such as “”, “ Vaekstforum for Region SouthDenmark, and will as part of the project document how it will create 300+ new jobs in the construction-industry before end of 2013.

To help answering the house owners question “what needs to be done”, the ZEROhome program offers a free energy review/consultation that is carried out in their homes. During the consultation the energy consumption is reviewed, improvement opportunities and cost discussed and a plan defined.

Expected results and benefits for climate change adaptation and mitigation

The climate change is an important issue to citizens of Sonderborg. The entire county is involved in the vision of creating a CO2-neutral growth area before 2029, creating and demonstrating new solutions, robust measurable CO2 reductions, new green jobs and a talented generation of young people. Far too long, the focus of climate discussions have been academic and political discussions mainly. In Sonderborg, residents since 2007 have taken action instead of talking. The public-private partnership – ProjectZero – was created to inspire and drive Sonderborg´s conversion into a ZEROcarbon community by 2029, based on improved energy efficiency, conversion of energy sources into renewables and by uniting all of the area’s stakeholders to reach a clear goal: CO2-neutral growth and sustainable urban development.

A house that produces more energy than its residents are able to consume, green district heating and ZERO+ companies, shops and schools are some of many examples of the new solutions developed by the area. Town residents are collaborating on new green investments, while farmers are erecting their own wind turbines, demonstrating the broad support for the ProjectZero vision.

In just three years, the area’s CO2 emissions will be 25% lower than five years ago. This goal will be reached by significantly more efficient energy consumption and increasing energy supply from the area’s own renewable energy sources.

Replicability potential of the practice

Everywhere. The Sonderborg area will serve as a role model for the rest of the world. Not by wagging fingers, but simply with a fundamental belief that we can utilise our energy much better than we do today. This applies to store owners, farmers and business leaders alike. And it applies to the area’s 18,600 home owners, who will now gain inspiration and knowledge about energy renovations that both ensure future housing values and reduce energy consumption. 1,200 homeowners will be offered free energy advice. More than 600 completed reviews have already sparked a growing demand for contractors who can implement energy renovations. The number of green jobs is growing – due to local demand, and because the ProjectZero vision bolsters exports and interest in area companies in many countries, including China.