Honey from your own roof

Rooftop gardening should already be taken into account in the building planning

We would prefer to have our buzzing colleagues right in the immediate vicinity. But for bees to feel comfortable, cosy beehives are not enough. Flowering meadows with a wide variety of flowers are their preference. However, they are not keen on long flight distances, so it’s an obvious step to create a meadow on the roof of the office building. "Rooftop gardening, i.e. the creation of a garden on a flat roof that is usually accessible, is becoming increasingly popular," says Axel Funke, Head of Sustainability DACH at Cushman & Wakefield. "But a little earth on the roof is not enough," explains Funke. "The feasibility must always be checked in advance, because with each bag of earth, you also increase the permanent loads on the roof. And when it rains and the earth binds the water, this can affect the load-bearing capacity. It is therefore advisable to call in a structural engineer at an early stage to evaluate the building and also possible measures to upgrade the lead-bearing structure."

"In the case of new buildings, however, green areas can already be considered during planning. Here, the builder only has to make sure that the roots do not pierce the waterproofing allowing moisture to penetrate into the roof. The roof structure is therefore a bit more complex – but nowadays this is easily possible," explains Funke.

Safety is also a top priority for roof gardens

Safety – for both bees and humans – is another topic in rooftop gardening. There must be no openings on the roof into which bees can fly and become trapped. Trees and tubs must be secured against falling over. In addition, technicians and facility managers still need to be able to access all technical equipment such as cooling units and antennae. The risk that people can be stung by the bees must also be kept as low as possible. Last but not least, the neighbours must not feel disturbed by the small beneficial insects. "To ensure that there are no misunderstandings here, we recommend discussing the project with the neighbours beforehand, making a preliminary inspection with the beekeeper and including the topic of "bees" directly in the contract with the facility manager," advises the real estate expert. If you are not the owner of the property, but a tenant, there are further hurdles, as the landlord has to realise all the framework conditions for the "Rooftop Gardening & Honeybees" project.  

Many paths lead to a greener property

So creating an idyllic roof garden is not exactly easy. But with good planning, a lot is possible. In addition, there are many other ways to make your own office building a little greener and more environmentally friendly. "Moss walls and vines, for example, are ideal for wall and fence greening and at the same time inhibit unwanted graffiti sprayers," Funke suggests. "In addition, environmentally friendly building materials can preferentially be used – even outdoors. For example, open-pore paving stones or water-permeable asphalt cost only minimally more, but these allow rainwater to soak into the earth. Another idea is the installation of photovoltaic panels, but issues such as regular maintenance, the feeding of electricity into the power grid and fire protection measures must be adequately considered."