Dachbegrünung

Dachbegrünung, also known as green roofing, refers to the practice of planting vegetation on the surface of a building's roof. This can range from simple sedum mats to extensive gardens with trees and shrubs, depending on the structural capacity of the roof. There are two primary types of green roofs: extensive and intensive. Extensive green roofs are lightweight, require minimal maintenance, and typically support shallow-rooted plants like sedums and grasses. Intensive green roofs are heavier, can support a wider variety of plants including trees and shrubs, and are often designed as accessible roof gardens.

The benefits of dachbegrünung are multifaceted. Environmentally, green roofs help to mitigate the urban heat island effect by reducing surface temperatures and absorbing solar radiation. They also improve stormwater management by absorbing rainfall, reducing runoff volume and slowing its flow into drainage systems, which can help prevent flooding. Furthermore, they enhance biodiversity by providing habitats for insects, birds, and other wildlife in urban areas.

Economically, green roofs can extend the lifespan of a roof membrane by protecting it from UV radiation and extreme temperature fluctuations. They also offer thermal insulation, reducing heating and cooling costs for the building. Aesthetically, they improve the visual appeal of urban landscapes and can create usable outdoor spaces.

Installation requires careful consideration of the roof's load-bearing capacity, waterproofing, drainage, and soil depth. A layered system is typically employed, consisting of a root barrier, a waterproofing membrane, a drainage layer, a filter fabric, the growing medium (soil), and finally the vegetation. While initial installation costs can be higher than for conventional roofs, the long-term benefits in terms of environmental, economic, and social advantages often outweigh the initial investment.