A paper by Dr.-Ing. Ferdinand Ludwig- Institute for architectural theory (IGMA), Daniel Schönle, Architect and Urban Planner and Ute Vees, Germany
Future oriented urban development concepts should maximise the quality of life for the inhabitants and at the same time minimize negative impact on the environment. A frequently used appropriate instrument to achieve this goal is to create big, ecologically effective open space, to plant as many trees as possible and to preserve old tree populations. Especially those have a huge positive impact on the urban climate by shading sealed surfaces and thus avoid the formation of heat islands, improving air quality and evaporating rainwater immediately to return it into the atmosphere.
Although all these positive facts are well known and highly accepted, trees are likely to have hard times in planning and implementation and are often sacrificed for other priorities. In short, the dilemma is that trees with their need of space are in competition with the densely built up areas of the city. But at the same time density is a prerequisite for many urban qualities: Only if facilities for housing and working, shopping, culture, education etc. are in close connection to each other a “city of short distances” and an “urban lifestyle” can emerge.
Yet we shouldn´t reduce trees solely to their ecological effect, but also see their aesthetic qualities. With their big canopies they have a high spatial presence and therefore are ideal elements to structure streets and squares. They are contrasting the hard and dead surfaces with liveliness and multi-dimensionality as well as they relativize the dimensions of tall buildings and bring them closer to human scale. This positive effect on the psyche and thereby the health of people is scientifically proved: Having only 10 more trees in a city block, on average, improves health perception in ways comparable to being seven years younger. City and nature seem appealing to people in the same degree. Already in 1927 Kurt Tucholsky described this apparently irresolvable contradiction between city life and nature in his poem “Das Ideal“ (“the ideal“) that is frequently quoted by architects:
“Ja, das möchste:
Eine Villa im Grünen mit großer Terrasse, vorn die Ostsee, hinten die Friedrichstraße; mit schöner Aussicht, ländlich-mondän,…“
(“Yeah, you’d like that:
A villa in the countryside with an ample terrace, faces the Pacific, backs up to Central Park with a nice few, rural and glamourous”)
The desire to transfer the qualities of trees into architecture is expressed in the tree house, which is neither a new nor an obsolescent idea. We can find examples in very different cultures and more and more also in contemporary architecture.
Very special kinds of a treehouses are the so called “Tanzlinden“ that have been widely spread over Germany and beyond from mediaeval times to the 19th century and partly still exist. By forming the branches of lime trees with elaborate horticultural methods and creating an inner green space in the canopy, here “tree” and “house” are merging into one spatial unit. In a similar way but primarily with a constructive approach, a tribe in Northern India, the Khasi people, is taking advantage of the growth processes of trees since centuries. In a process that lasts over generations they are interweaving the aerial roots of the Indian rubber tree to merge them into framework like structures and living bridges spanning up to twenty meters wide canyons and rivers emerge.