Roof afforestation is the roof cover of the future. It will be natural to have a forest, or a wild meadow, or a vegetable garden on your roof.
It will be hard to imagine that there ever was a time when roofs were dead, without life, without vegetation.
It is self-evident that territories, which we illegally took from nature, must be restored in the course of peace with nature. One of these illegally usurped territories are the roofs, i.e. the pristine areas we destroyed; since we are building, we must restore these destroyed territories on the roofs.
But careful, it must be untouched nature that we help restore to its own right. Since, when entering into a peace treaty with nature, we must do this with an independent and free partner, not with a subordinated slave. Our gagged, disenfranchised, mono-cultured, regulated, poisoned and nursed-back nature cannot be an equal partner to man.
A reverse trend is developing. What had thus far been seen as right, the subordination of nature, has not only proven to be wrong, but lethally dangerous for man himself. The straight line and its shapes cause cancerous formations, not only architectonically, but also medically speaking.
Our intimate one-on-one relationship with nature must be restored. This one-on-one relationship is now incomparably more important than human relationships, and is tremendously complex.
It is not only about the fact that plants feed us and enable us to live all over the world, e.g. by providing the oxygen we breathe and the pure water we drink, but that through nature, we get to know the nature of creation, the nature of creativity. As an artist, I am becoming more and more conscious that nature's and man's creativity must be reunited, if we all, God's own image, want to survive on this Earth. In the cities, and now unfortunately even in the country, we have distanced ourselves so far from true nature that we are in danger of giving up our existence. Especially in urban deserts, roof forestation is an absolute duty.
For too long, we have been living according to the maxim: Let's subdue nature. Now it is time to undo this wrong by placing ourselves underneath nature, i.e. having nature above us, untouched nature, instead of flattening and destroying nature.
Technologies for grass, forest, garden and trees on the house are so advanced that there is no longer an excuse not to have a grass roof. Those who do not have access to a roof can cover their window with greenery and share quarters with a tree tenant, a tree growing out of the window.
I have demonstrated grass and forest roofs in New Zealand and in Löwengasse in Vienna, which are a great success. In Vienna's Löwengasse, 900 tons of soil were applied to 13 nested roofs and planted with 250 trees and shrubs.
A bird's-eye view shows the house completely green. An area even larger than the entire lot is covered in greenery, since the planting also reaches into roofed-over floors, and 5 tree tenants result in additional green space.
A roof forestation is an unbelievable positive thing. It brings advantages, joy and well-being, not only to those using such a grass roof (Just think: a piece of meadow and forest in the middle of the city), but also to those living underneath such a piece of nature: an indescribable feeling of pleasant warmth and cooling at the same time, a feeling of safety from fall-out or radioactive radiation, and a smell just like in a forest, but without the humidity.
Moreover, the grass roof brings great advantages also to those who neither use it nor live underneath it, those who enjoy its sight, a passer-by, the inhabitants of surrounding houses, who, instead of onto barren roofs and bleak houses, look out onto living woodlands, with all the wonders of nature changing leaves, blossoms and fragrances through the seasons. Furthermore, those not living in the grass house have the advantages of reduced dust and noise, better air quality and a better climate.
In order to understand how positively a grass roof affects the psyche and well-being, one only has to sleep underneath a grass roof once. It is a completely different feeling of liberation and security, and many other unspeakable things. If a grass roof is well made, one is spared from any roofing work or repairs for at least one or two generations. One has the good feeling of doing one's duty and living in peace with nature, and one sets a good example.
A piece of advice from experience: The edge holding the grass roof's soil should be coloured dark, i.e. dark brown or black - made of stained wood or cement, never white or in bright concrete colours, since in our corner of the world, only dark colours, especially dark brown, go well with grass green and the colour of soil.
Whether the grass roof should be mowed once a year or not at all, and whether it should be irrigated or left to its own devices, is up to the individual. Grass roofs shrivelled in summer will turn green on their own in spring or fall and after long periods of rain and even during snow-free winters.
I advise against bituminous roofing felt as a layer of insulation, since the roots grow through it; in my experience, plastic foil works best, if made from one piece and not glued. Overlaps must be at least one meter.
The grass vegetation is different each year, which is amazing. The sowed grass or the rolled out lawn are replaced each year by other types of grass and plants through seeds or flight of birds - a constant transformation.
On my grass roof in Vienna, I have seen and photographed bees, butterflies, beetles, blackbirds, and even a wild duck breeding its eggs.
written as preface for the following publication:
Roland Stifter, Dachgärten - Grüne Inseln in der Stadt, Stuttgart: Verlag Eugen Ulmer
Schurian, Walter (ed.): Hundertwasser - Schöne Wege, Gedanken über Kunst und Leben. (Beautiful Paths - Thoughts on Art and Life) Munich: Langen Müller Verlag, 2004, pp. 246-248 (German)
Hundertwasser. New York: Parkstone Press International, 2008, pp. 168-171
Hirsch, Andreas (ed.): Hundertwasser - The Art of the Green Path, Exhibition catalogue KunstHausWien. Munich: Prestel Verlag, 2011, p. 165 (excerpt)