From the outside, its appearance was less than inspiring! Strangely, while the interior felt coherent and integrated, the exterior seemed fragmented and rather hotchpotch. External materials were a mixture of timber cladding and render with grass and metal roofs. We learnt that several architects were involved, each designing one of the school's 'departments', to a common set of principles, which included ecological design among them.

Liz McLean

Joachim Eble's Kindergarten at Pfennigacker was a complete contrast. Although it too has a linear form, it is divided into two storey 'houses', each clearly articulated externally and each with its own external access stair. Its form reflects its Steiner educational roots where children have the same base from year to year. Its scale is warm and intimate, reflecting the needs of younger children, by contrast with the grander, more sociable scale of the school at Kalon. Everything about Eble's school is refined and thoughtful. Although it has quite a complex plan and sectional form, a common palette of materials and colours underlies each element and ties it together to read as a coherent whole. This building gives a lie to the sometimes-heralded thought that ecological buildings are dull! It is crisply detailed, with horizontal and vertical boarding articulated by different colours – subtle earthy blues and oranges and yellows developed by Joachim's wife Barbara, with Keim Mineral Paints.

Perhaps the most interesting feature of the building is its use of 'brettstapel'. This is a factory finished, structural panel made from strips of timber about 38mm wide and varying in thickness depending on its structural use. Unlike laminated timber, these strips are nailed together rather than glued. In development is the next generation brechtstaple, which will use oak dowels instead of nails, enabling the panels to be cut more easily. This is a wonderful component, potentially providing all in one structure, wall and finish. Used with concrete, it provides fire protection to the floor structure. By forming grooves and hollows between the timber strips, the panel achieves excellent acoustic qualities. Inside the school, Barbara has used Keim coloured stains on the brechtstaple to great effect.

The external envelope uses cellulose insulation, with a mixture of sedum and aluminium roof finishes. Aluminium was the subject of some debate amongst the group, with its use defended by Eble as being acceptable where longevity and robustness was important. Whatever the debate, we were impressed with the rigour with which Joachim applied ecological principles to all of his work, not as a bolt-on, but as an essential way of providing delightful, benign buildings and human habitations.

Liz McLean

This was one of the very first major residential ecological design projects in the world.

The Layout of the 220 House development is notable for the fact that it delivers a high density development with a very human scale without resorting to the tower block model of the housing adjacent to the site.

The vernacular style developed for the project was taken from studying the scale, materials and proportions of a neighbouring village, and is particularly successful at avoiding pastiche.

It has eco-labelled materials throughout - based on Baubiologie principles. The majority of the construction is of brick (lower walls) and timber (upper floors) and all finishes are of low emission materials (lime plaster and organic paints etc.) Th floor construction is of beams carrying bricks in order to obviate the use of concrete and a natural timber board floor finish over a sound absorbent sandwich gives a very neat inter-flat detail.

The Landscape strategy is particularly impressive - especially now that the courtyards are mature - indeed there has been tree surgery of fairly drastic proportions to cope with the intensity of the growth over the years. The use of porous surfaces and the 100% pedestrianisation of the whole project interior give a sense of human scale and a very distinctive sense of being close to nature. This feeling is clearly identifiable in other projects but this one has the advantage of age and maturity, where the others are still in their nursery stage.

This project has been a major influence on other ecological designers because of its consitstency and its clear success as perceived 16 years after its completion.

Howard Liddell

The Prisma Building, designed, by Joachim Eble, is among the most important contributions to urban design and ecotecture of the end of the last century. This is fresh healthy urban tissue, grafted into the urban context at a high density: plot ratio circa 3.6 and up to seven floors.

It is therapeutic and ecological in many ways: firstly in a sympathetic contextual sense, yet making a strong architectonic statement to the street, where the ‘prism’ of glass is expressed in a restrained, yet playfully assertive way: it says “I am” in a ‘peekaboo’ moment intriguing the passerby. One is led into the wonderful garden room: leaving the traffic noise, pollution and the alienated world of conventional ‘big city’ outside. The aromas of growing things and natural materials are immediately affecting; as is the sound of running water and the wonderful colours of the gestural timber columns supporting the high glazed roof. This superb timber structure is dancing in ‘eurythymy’ as you walk around in the space: the profusion of planting is gentle yet elemental; the sound from the cooling and refreshing water walls is calming and the sight of the wonderful polychromatic glass art on these is moving: you feel it all in YOUR waters!

The colour work by Barbara Eble is here really quintessential: the use of recessive blue and ochres / burnt orange and subtle violet all work wonderfully in this true ‘music of colour’. The glazed garden room gives onto the open air courtyard overlooked by the kindergarten and many other uses. The mixed layered use is very striking: from a busy ground floor with many shops and a cafŽ to upper levels of offices, some giving onto the big garden room, some to the street; some to the open landscaped courtyard: there are dwellings at the topmost level in a seven storey building in all. THIS is the sort of place I should like to live and work in: this is music of the future: the Ebles have much more to give us.

Prisma is published inter alia in the AR July 1997 but nothing will replace a visit to this important, fully achieved seminal piece .

Paul Leech, Dublin