Such an investigation can not only cost thousands of euros, it can also take longer than a year, says Valeska Hovener of the Eigen Huis Association. “And sometimes longer, because there are so few ecologists.” VEH therefore decided today to stop offering cavity wall insulation to members. The homeowners’ association wants the government to oblige every municipality to have an SMP. “So that they have an accurate map of where bats and other endangered species are and where this may come into conflict with houses,” says Hovener.