The Villazero project was born out of the dream of building a sustainable single-family home. The three companies Fiskarhedenvillan, Mondo Arkitekter and Structor Byggteknik Dalarna started working together to fulfill that dream. The project chose to focus on reducing carbon dioxide emissions and decided to build a carbon dioxide-neutral villa. The NollCO2 certification developed by the Sweden Green Building Council has been followed with the basic Nordic Ecolabel.

Pia Stoll, who is a senior expert at the Sweden Green Building Council, explains that Villazero has been a special project for them as well.

- Villazero is NollCO2's first certified detached house project and has been a pilot in the development of certification. We were unsure whether it is possible to reduce a villa that is usually built of wood by another 30 percent, but those involved have shown that it is possible with good cooperation and curiosity about new solutions. In the next manual version, we can now add detached houses as a building type that can be certified with NollCO2. Cool!

Neutral within ten years

Certification according to NollCO2 has two main tracks. One requires that the building's greenhouse gas emissions are reduced. In addition, the certification requires that the building balances the climate impact that remains to net zero. This can be done with climate measures such as the production of renewable energy, such as solar panels that Villazero has chosen to use.

Thanks to the fact that the house is built very energy efficiently and has been equipped with an efficient photovoltaic system, the house will quickly pay off the carbon dioxide debt that the construction has caused.

- The requirement from the certification is that the house must repay the carbon dioxide debt within 50 years. But we have had a much higher ambition than that, Villazero will be neutral within ten years, says Erik Jäderbrink, business developer at Fiskarhedenvillan.

Built on wooden foundation

Villazero is now completed in Borlänge, Sweden. The house has received a lot of attention both in the Swedish construction industry and internationally. It houses four rooms and a kitchen on its 107 square meters. Both walls and ceilings are made of wood, which is not painted but treated with silicon to resist moisture and rot. But the choice to build the house on wooden foundations has been particularly debated.

- We have evaluated several basic types, including solid wood foundations and light floors. The lightweight flooring alone actually had even lower impact, but since plinths would then be required, cross-glued wood still ended up at the lowest. Under the wooden board are four layers of EPS insulation to protect against moisture from below. In addition, the wooden board is clad in a protective membrane, a diffusion-open foil that protects against moisture and dirt, explains Anders Berggren, building designer at Structor Byggteknik.

Villazero will continue to be researched even now that it is completed. With the help of moisture sensors in the foundation, walls and ceiling, the project team can follow how the materials and methods will work over time.