Insect habitat systems integrated into façades-impact on building physics and awareness of society

Deforestation, intensive farming and the sealing of green spaces are considered to be the main reasons for the global decrease of biodiversity. In this context, the built environment, and in particular vertical surfaces, are still highly underestimated and need to be taken into account. Although it is acknowledged that greened surfaces have beneficial effects, for example, on the microclimate, the vast majority of buildings are still not biodiversity-friendly. Artificial nesting boxes help birds and bats adapt to the change of their habitats. However, insects, with their tremendous significance for insectivorous species and for humans, are mostly neglected or even threatened. The purpose of this holistic approach is to investigate interactions between integrated insect habitat systems in façades and building physical aspects to create test objects. Heat transfer coefficients, thermal bridges, and the risk of condensation inside the buildings were simulated in different arrangements of nesting boxes for wild bees. As a result, conclusions on heat and humidity protection in ventilated façades and external thermal insulation composite systems could be drawn. The following results showed the maintenance of indoor comfort and energy efficiency as well as a low risk of mold. Further investigations analyzed the sound reduction index and fire protection. From a building physical point of view, integrated insect habitat systems could be part of the constructed environment and even link inner-city biotopes. Further challenges and opportunities are identified rather at a socio-ecological and technical level. Without taking into account the civil society and ecological demands of the various species, habitat systems for insects will miss their objectives. Special focus will be put on the skepticism and lack of knowledge of people, as well as on the comfort of the insects.