His plans stem from the fear that the climate is really going in the wrong direction if we do nothing. Bart van den Hurk of Deltares and Liselotte de Koning van het Rode Kruis Princess Margrietfonds also warned about this at the start of the Climate Work Conference : we have now reached a point where natural phenomena reinforce each other. The CO2 emissions cause higher temperatures and that in turn leads to more heat and drought, more extreme precipitation, more hurricanes and cyclones.
The ultimate goal of the ecovillage is for Boekel to become climate-proof and climate positive. For example, the ecovillage is not connected to the sewer. Instead, residents purify the wastewater in the neighborhood itself. Under the houses is a water storage of a total of 90,000 liters filled with rainwater. "In the event of extreme drought, 9,000 litres of water still go into the soil every day. In every other district, the groundwater goes down, with us it remains the same," says Vlems.
He explains that this is because the inhabitants do not wash away the water through the sewer, but literally purify it on location with the help of a helophyte filter. "That filter purifies wastewater with the help of plants to a quality that is harmless to the environment."
"In every other district the groundwater goes down, with us it remains the same"
In addition, the residents collect as much rainwater as possible, which they use for washing machines and flushing the toilets. Vlems: "An additional advantage is that much less detergent has to be used, because rainwater is lime-free."
The houses are made of 38 centimeter thick lime hemp walls that keep the heat inside and the cold out. Vlems notes that the use of such walls is climate positive. "The building materials used store more CO2 than was needed to build them."
In winter, the houses are heated through an invention of Cees van Nimwegen. He developed a battery in which heat is stored using steel slag, a waste product of precious metal. "The heat generated by solar panels will soon be stored there. In winter, all 36 eco-homes are heated via underfloor heating. There is no gas or electricity involved."
The battery box heats up to 450 degrees in the summer. If the houses need to be heated, air is blown through them. And via a boiler, that heat goes to the houses. When asked whether this system can also be used for large-scale construction, Vlems answers in the affirmative. "It is designed in cubes of 1.50 and 4 meters that you can scale up. The minimum amount of homes you can heat with it is 30. Unfortunately, you can't place a battery in your backyard for the time being: the smaller the volume, the greater the loss in storage."
The solar panels in the ecovillage are made of glass on glass and therefore calculated for heavy hail. The roofs themselves are protected from heat stress, and the 38 strategically placed trees also help against that. "If our tanks become empty in the event of drought, we are the only village of the water board that is allowed to pump water from the bottom, from the enormous reservoir that lies under the houses."
With all these innovations, financing proved difficult in practice. For example, Vlems talks about a reaction he received when he presented his plans at the invitation of a number of banks and funds. "Every innovation means a higher risk. You have so many innovations that we cannot calculate what the possible joint risk is," one of the bank employees told him.
In other words, ecovillage Boekel would have to pay high mortgage rates. Impossible, says Vlems. "We're building social housing, so we can't afford high interest rates." In the end, a German bank with experience in the field of residential communities offered a solution by offering financing.
"Every innovation means a higher risk"
His message is clear: giving credit for innovations is difficult. Precisely because it is new. As a result, an insurer does not know what risks are associated with this. Vlems: "Nevertheless, Achmea decided to insure the innovations. Especially because they still see few initiatives from people themselves and they would like to stimulate that."
All machines, pipes and homes are insured by Achmea, because the ecovillage contributes to sustainability. Moreover, Achmea not only provides the insurance, but also experiments. For example, Zilveren Kruis is conducting a trial with instruments that measure the air quality in the homes and where an alarm bell goes off if there are harmful substances in the air. In addition, the insurer's experts think along about the safety of various innovations. For example, about the battery. "This way, the residents stay healthy longer and there are fewer costs. Because prevention is better than just insurance," says Vlems.