LOG ID logic - apartment building in Biel, Switzerland

Architectural Review, The, Sept, 1996 by Herman Geest

The well-tried strategy for power saving and use of ambient energy of the LOG ID practice is deployed on a housing scheme in Switzerland.

LOG ID of Tubingen have featured on these pages several times in the last few years.(1) The multi-disciplinary practice, which includes botanists, doctors, physicists and communication psychologists as well as architects, was one of the first to articulate a clear programme for a sustainable architecture that could reduce our consumption of fossil fuels and cut down pollution by using solar energy and the properties of plants. They call their approach `green solar architecture' and its principles are very simple: glass passive solar collection spaces face the sun; massive structures behind act as thermal fly-wheels and protection from the cold of the north; semi-tropical plants are always introduced to absorb carbon dioxide, emit oxygen, reduce pollutants and add to summer cooling by transpiration.

One of the practice's latest buildings is private apartments in the little town of Biel, at the top end of the Bieler See in north Switzerland. In collaboration with ASP, a local architectural firm, LOG I D worked out a strategy for dealing with a suburban site that slopes very steeply to the southwest overlooking the town. Of course, this is perfect topography for the practice's approach, and the firm responded to the brief for eight dwellings of different sizes with a scheme that has large glass houses on the front of a lower tier of maisonettes, topped by flats, themselves fronted by similar glass structures. All units have balconies, and the flats have splendid roof terraces as well.

The section throughout is split-level, giving the maisonettes double-height conservatories, and the flats above one-and-a-half storey glass houses. These glass spaces are, of course, much used in summer, but they are not usually intended to be heated in winter. In the coldest months, they become thermal buffers, closed from the inner living rooms by folding glass walls. Enough heat from the inner areas of the house escapes through the movable partitions to keep the temperature of the winter gardens high enough to sustain the plants (except in the most extreme external conditions, when a boost is needed).

The latitude and height of Biel ensure that the site enjoys many sunny winter days. Then, the inner glass wall can be taken back and the winter garden amalgamated with the living area again; meanwhile, the massive structure of the interior absorbs heat from the low sun through the glass and re-emits the warmth at night.

In summer, the glazing at the front of the dwellings can be opened to create thermal chimneys which draw air through them by convection (and create a sucking effect from the cool back to the hotter front). In the coldest, darkest days of winter (and of course on many evenings and nights) the inner glass wall is shut, focusing life in the inner recess, which still enjoys wonderful views over the town through the leaves of the conservatory plants.

The only place where the design strategy can be faulted is at the back, where glazed galleries run inside a dark, deep and narrow ditch that has been cut into the hill to allow access to the dwellings. It might have been much better to have made the galleries open and glazed the top of the trench, for glassing over even the most dull and cramped external space always has the effect of making it indoors, and hence more genial. In detail, there are some touches unusual for this practice, which usually plays with a very straight bat: winsome little gables and rather silly stuck-on balconies in the middle of the front. Perhaps these gestures were thought necessary to attract the clientele.

Though the building is plainly one for wealthy people, its thoughtful approach to dwelling and climate can plainly be reinterpreted at more modest levels. It may not be a universal nostrum, but it does achieve a reduction of 20-30 per cent of heating energy needs by using solar warmth. It adds the unquantifiable benefits of the plants -- and the Log ID policy of adopting building materials and products which need little energy to make and give off very few harmful substances. The basis of the design is a reworking of a well-established strategy but the scheme shows how it can be extended to a hitherto unexplored building type.

[1] For instance, February 1993, december 1994, May 1995.