Passivhaus Solutions to Stop the Advance of Radon Gas

Sustainable houses are the immediate future of ecological construction - and they are even one of the best options to comply with the upcoming Nearly Zero Energy Buildings - but they are also positioned as a great option for enjoying the best air quality in our homes. Not only against pollutants coming from outside but also against radon gas, a poison that originates in the soil of some Spanish regions. A threat to which the certifying label Passivhaus offers us its solutions against radon to prevent its damage in our homes.

It is the certifying association itself that has wanted to join in the alerts about the dangers of radon gas. On its website, it has explained that, according to its research, the communities most affected by this poison that originates in the basements of many houses are Extremadura, part of northern Andalucía, Galicia, Castilla y León, and some areas of Madrid like the Guadarrama mountains. These conclusions are quite in line with those found in the map of radon gas.

As the German origin label reminds through its page on the Passivhaus Building Platform, radon gas is colorless, odorless, and tasteless. Practically undetectable, which means we don't realize its presence until it's too late, unless we have sought professional help beforehand. However, its consequences are very severe: radon gas is the second leading cause of lung cancer cases, just after tobacco, as reported by the World Health Organization.

The origin of the gas is found in uranium stored in the granitic areas of our territory, as well as untreated mountain waters, poorly conditioned building materials, and rocky walls of many caves. It seeps into our homes through affected basements and in houses with poor ventilation.

"Radon gas enters homes through uncontrolled cracks and air intakes," explain those from the Passivhaus platform. What is the solution according to the certifying label? "The best way to avoid it is to ventilate the basements and sanitary chambers of buildings before the gas reaches the house." And one of the significant risks is that, once inside the home, it is not enough to use natural or hybrid ventilation. This is why Passivhaus warns that the best option is to use mechanical ventilation with heat recovery. The only way to ensure the gas is expelled from the home.

What solutions against radon do passive houses have?

However, appropriate measures have been taken, and it is anticipated that the panorama facing radon gas will be very different in a short time. For example, it is expected that the Technical Code for Building will include a revision establishing a maximum allowed presence of this gas. Experts communicate that it should be a maximum of 300 becquerels per cubic meter of air (Bq/m3) in habitable spaces.

Why can Passivhaus passive houses be a good way to protect against radon gas? Basically, because they incorporate mechanical ventilation and heat recovery systems. In this way, stale air is automatically eliminated from the room at all times. Likewise, these systems renew the air even when no one is home, without the need to open windows.

Passive houses are also built in such a way that cold and heat cannot penetrate due to the high airtightness they achieve. In the same way, gas cannot filter into these homes, even if they are in high gas concentration areas.

We can say that the solution to radon gas in a highly affected area does not have to be moving to another place. One does not have to leave a family home or abandon a house because of it. With good ventilation, like that offered by passive houses, solutions against radon are provided. And in this case, it is not only the Passivhaus label but any other reference, such as the BREEAM sustainable construction certification.

Passive houses are one of the main solutions against this poison, but with the installation of a mechanical ventilation system with heat recovery, which removes the air from the rooms and introduces fresh air from outside, filtered and free of impurities, any home can combat radon gas.