Being consistent with its values and leading by example: these are the intentions behind the renovation of Raphaël Domjan’s house in Cortaillod. Inaugurated this Friday, the Neuchâtel eco-adventurer’s project was completed four years after its launch.
The work has made it possible to densify the living area and make this building a positive energy residence. Originally, the building was 60m2 and could accommodate two people. Today, it is 200m2 and up to seven people can live there.
This unprecedented project in Switzerland, according to Raphaël Domjan, does not emit CO2 and should produce almost three times more energy than it consumes. The construction is mainly made of wood, thus limiting the use of concrete which produces CO2, by a material which stores it. For the rest, the use of ecological concrete developed by Marti Arc Jura in Cornaux and the start-up Neustark reduces the amount of CO2 emitted by around 15%.
Another example of installations, thermal solar panels are used to produce domestic hot water and reduce electricity needs. This hot water will also be used to recharge the geothermal probes of a heat pump.
The excess energy produced will be reinjected into the network. And in case of energy shortage this winterthe facilities should allow residents to live normally for a few days.
If the installations allow greater energy autonomy, they are not enough to be 100% self-sufficient. A choice that Raphaël Domjean justifies by a collective interest in benefiting from the surplus energy produced by this dwelling.
However, these installations are 15% more expensive than a standard construction. A project that is therefore not within everyone’s reach: “But as energy is very expensive today, in the long term, a positive energy house makes it possible to save money compared to houses heated by gas or oil. In addition, the eco-adventurer believes that some facilities are affordable. For example, building a house out of wood does not cost more than concrete and certain technologies are inexpensive, according to him.
It now remains to measure the efficiency of the house. To verify the hypotheses of energy consumption and production, the dwelling is equipped with a measurement system. /cde