Solar gain.

This house is as close to being a living organism as contemporary technology can provide. Its systems for using ambient energy and rainwater, and its indeterminate form ensure that it can grow and change with the lives of its occupants.

There are perhaps two images of the ideal house as different as the visions of the ideal woman by Rubens and Botticelli. In architecture, the analogy of the latter is possibly one of the elegant, minimalist houses by Alberto Campo Baeza or Claudio Sylvestrin, perfect figures and spaces beautifully formed with great precision in space and light. The Rubens analogy suggests an altogether more elaborate and abundant approach, akin perhaps to the most genial moments in Kroll and Scharoun's work, full of unexpected warm and genial happenings.

Thomas Spiegelhalter's house at Breisach am Rhein is definitely at the Rubenesque end of the spectrum. Spiegelhalter calls himself a sculptor and architect, and it is difficult to draw a line between the two scales of his work, which at first seems to have emerged out of a wild romance between Kurt Schwitters' Merzbau and Gunther Domenig's Carinthian surrealism (AR April 1996) with Co-op Himmelb(l)au somehow acting as intermediary. I hope that I have set an appropriately sensual tone in the opening of this article for you to approach the house as an organic entity. But at first, it scarcely seems to hang together at all. Every opportunity is taken to emphasise the differences of the parts, whether they be caused by changes of use, material ortechnology.

The house is made for an academic couple with children; they wanted to make an ecologically responsive building which would have opportunities for organising small concerts and exhibitions. For all its apparent chaos, the house is generated by rigorous functional and energy-conscious programmes It has 16 different levels, but they can be broadly divided into three main zones above the garage in the basement. In the lowest zone is a large room in which the owners can have many different kinds of performance -- the 'media hall' which has a separate entrance from the domestic areas. In this zone too are the main elements of the house itself: the double-height living room, the conservatory and kitchen. In the zone above this, there is the main entrance to the dwelling itself, with a solar-glazed hall which opens off a curved ramp that brings the inhabitants up over the public entrance to the media hall. From here, a balcony opens to look down into the living room, and two of the major subsidiary living spaces spin off (these can be used for sleeping in, or as studies or parlours). In the zone above this are rooms that will plainly be mainly used for sleeping in, a `tropical bathroom' end green planted terraces.

All these functions are, remember, arranged with many different small changes of level. These, with the fluidity of the planning, ensure that there is a constantly changing kaleidoscopic sequence of spatial experiences: views, long and short up, down and diagonal, all carefully varied so that almost every walk through the place offers a different scenario. The whole operation is drawn together round the central spiral stair, from which all the spaces spin off centrifugally.

In constructional terms, the house is essentially in two parts, with a massive masonry building of straightforward kind surrounded on its sunnier sides by lightweight constructions of various types which allow controlled solar gain. The changes in the latter work -- the moves from glass to metal siding to rough timber, for instance, are plainly partly playful. But they are rather more than that. Solar energy is utilised in two ways, first with a hot water system that uses tubular vacuum collectors on the roof which with a highly sophisticated control and storage system provide the house with most of its domestic hot water and central heating requirements.(1)

The second way in which solar energy is used is made dramatically clear by the huge (45 [m.sup.2]) battery of photovoltaic cells supported on lattice girders and slung between the second and third zones of the section round the south side of the house over the entrances. The German Government has subsidised the installation as an experiment, and the architect hopes that the system will be so efficient that it will be possible to feed power (after rectification to alternating current) back into the national grid.(2)

The fabric is almost as much imbued with green consciousness as the systems. Spiegelhalter is obsessed with the local gravel pits near Freiburg where he works. These contain strange industrial structures (now mostly abandoned) which have changeable lightweight elements married to heavy concrete and masonry bases. He has been able to use fragments of the gravel pit buildings in the house, and has projected the aesthetic into a domestic scale with the rough wood, industrial siding and standard off-the-shelf components.

Internally, the detailing, which outside retains a robust solidity, moves from the wacky to the twee (particularly in elements like the balustrades, where you almost cry out to the architect as if to a naughty child who must be told to STOP FIDDLING). But of course, this house is far more than a collection of childish gestures. It tries to relate humanity to nature in very many different ways, ranging from the sophisticated photovoltaic electrical system to the elemental possibility of waking up on the top levels in a room filled with the scent of herbs from the terrace. And it gives ecologically conscious architecture a human face -- it can be fun, as well as efficient. Spiegelhalter calls the house a `work in progress', and so it is, for doubtless it will grow and change as its owners do. It is robust enough to take all manner of alterations and should become part of the family.

(1) There is a natural gas engine which provides heat when solar energy is deficient. The 600 litre warm water storage capacity of the system is 18 times the daily consumption of an individual.

(2) A further ecologically sensitive system is a rainwater conservation arrangement that feeds the lavatories and waters the garden. It has two tanks on the roof which Contain 7000 litres.