Green, planted facades are in fashion at the moment. The positive effects of verdant walls may be compared with those of planted roofs: the retention of rainwater after heavy precipitation, an improvement of the microclimate, the reduction of intense local heat gains in cities, energy savings as a result of vegetation screening the building skin against wind, the cooling effect arising from evaporation, the absorption of traffic and other noise, an improvement in the quality of the atmosphere through the dust-trapping effect, the avoidance of graffiti and the visual upgrading of unattractive existing facades. Planted walls help to create biodiversity, although there may also be problems with insects and mice.