LLEIDA – The newspaper Nius wrote about ‘positive houses’ in the Spanish Pyrenees. In these houses, It is 20 degrees in winter without heating. The houses are completely self-sufficient with solar energy and go a step further than the efficient homes already on the market.
Owner Jordi Oliveres regrets that we use fossil fuels in a country like Spain with so much sun. His ‘positive house’ of 220 square metres is located in La Pobla de Segur in the northern Spanish province of Lleida. The owners speak of ‘positive houses’ because they keep their houses warm without using gas or electricity from the mains and they generate more energy than they consume.
Self-sufficient house for €250,000
Kike Herrera is also the proud owner of a ‘positive house’. He lived with his partner and two young children in a very cold and damp mansion. He was inspired by acquaintances who also built such a house, with local materials and not much more expensive than a normal house. “They opened our eyes,” he says in Nius. His house cost €250,000, including the purchase of the land, the architect and the construction.
The main wall captures the heat from the sun during the day along with several photovoltaic panels that capture the electrical energy consumed. The thermal insulation of the house retains this heat during the night so that the occupants do not need heating.
“When it is -5ºC outside in winter, we never go below 19ºC inside. Only on days when the sun is not shining at all, we turn on a small heater that distributes heat throughout the house,” he explains.
Surplus power for the rest of the city
Although the house runs entirely on electricity, the solar panels provide more energy than the family consumes. They also charge an electric car that drives 4,000 kilometres per month. “We transfer the excess energy to the electricity grid, which distributes it throughout the city. If we run out of power at night, we use the network. The balance is always positive,” says Kike. They pay no more than €15 per month for electricity which corresponds to the capacity.
The family is “extremely happy” in their ‘positive home’. However, they do indicate it is much more difficult to maintain thermal comfort in the summer. The first summer they got through, it was sometimes 40º inside. However, this summer they used an energy-efficient air conditioner. It used solar energy and was turned on during the hottest hours of the day. Then it did not get warmer than 25º in the house.
The type of house requires a certain dedication
According to Kike, the investment in insulation is high, but investing in a heating system is not necessary. He further acknowledges that this type of house requires a certain commitment: “You have to think about opening and closing blinds during sunny hours. But I see it as a positive thing that we live and benefit from the elements of nature”.
Constructions that insulate in the winter and ventilate in the summer
Josep Bunyesc is the architect of the houses of Jordi and Kike: “The south-facing facade catches the sun in winter and we give the whole housing a good thermal insulation. The house then retains the heat collected at night. It works the same as a thermos,” the architect explains to Nius.
According to the architect’s data, the temperature in the room of the houses reaches 23 or 24 ºC during the day and drops to 20 degrees at night. In the summer it gets to 26-27 degrees during the hottest hours. Then ventilation is important. The house is protected against the sun by sun blinds and vegetation and ventilation ensure cooling.
Furthermore, the architect uses the lowest possible environmental impact of renewable materials. Most of these houses are made of wood, and natural stone and use natural insulation of (vegetable) fibres such as wool or cotton.
Bunyesc acknowledges that interest in this type of housing has increased over the past decade. One of his most recent projects is the construction of 12 homes in Òrrius, near Barcelona. He also built two mountain huts at an altitude of 2,500 metres, without heating, where it is sometimes still 30º in winter.
Rapid evolution in a few years
Jordi Oliveres was one of the first clients in the region to believe in this philosophy. This environmentalist built his house in La Pobla de Segur in 2014: “In eight years, the finishes have evolved enormously. Kike’s house has elements that mine did not yet have “, he admits. His is all wood, it’s in a valley next to a river.
He pays €100 a year for electricity plus fifteen bags of pellets for a stove that they only turn on when the sun isn’t shining and they can’t capture solar energy. Jordi encourages others interested in building: “Word of mouth helps here. If you see a neighbour who has it and is happy with it, it’s easier to spread the word.”