The New Engineer

Citation: This is article was published as Sharon Beder, 'Designing for sustainability', Engineers Australia, December 1999, p. 65.

This is a final version submitted for publication. Minor editorial changes may have subsequently been made.

Sharon Beder's Other Publications

Modern engineering design has been characterised by the incorporation of economic considerations as an inherent and inseparable part of the design process. Ecologically sustainable design would similarly require the incorporation of environmental considerations as an inherent and inseparable part of the design process.

Pre-industrial design tended to evolve over hundreds of years by trial-and-error in what Christopher Jones has called a "slow and costly sequential searching for the invisible lines of a good design". The final result was often "an astonishingly well-balanced result" which was well suited to the needs of the user.

Products were bound to adapt towards an "equilibrium of well-fitting forms" because the only incentive to change was when there was a misfit. Any failure of a product to fit its context properly was corrected on the spot, often by the user who was also the builder. Christopher Alexander gives the example of African mud huts in the French Cameroon:

"Whether by coincidence or not, the hemispherical shape of the hut provides the most efficient surface for minimum heat transfer, and keeps the inside reasonably well protected from the heat of the equatorial sun. Its shape is maintained by a series of vertical reinforcing ribs. Besides helping to support the main fabric, these ribs also act as guides for rainwater, and are at the same time used by the builder of the hut as footholds which give him access to the upper part of the outside during its construction. Instead of using disposable scaffolding (wood is very scarce), he builds the scaffolding in as part of the structure. What is more, months later this 'scaffolding' is still there when the owner needs to climb up on it to repair the hut."

Design methods changed with the changing requirements of industrialising nations. The traditional evolution of forms was no longer fast enough to keep up with the constant demand for new products in rapidly expanding economies. The design process was removed from the site of manufacture to the drawing board where scale drawings were made. The designer now had to achieve "in a few hours at the drawing board what once took centuries of adaptation". The scale drawing became the medium for experiment and change.

It was not just the move to the drawing board that transformed engineering design. Engineers were increasingly expected to incorporate economic considerations into their designs and streamline their use of materials. The push for the increased scientisation/mathematisation of engineering design came in large part from the desire to keep manufacturing and construction costs to a minimum. The requirement of minimum material for engineering design is illustrated by the example of Robert Stephenson whose railway bridges were made of "huge rectangular tubes of steel". Stephenson wrote to Roebling who was planning to use a suspension bridge to carry trains across the Niagara: "If your bridge succeeds, then mine have been magnificent blunders."

Economic considerations have become an integral part of engineering design and a force for refinement and sophistication of design methods. But this is often at the expense of other design considerations. The increasingly scientific/mathematical nature of engineering design has the drawback that, unlike the former craftsmen, designers are weaker at judging the compatibility of a designed product with its environment and the context of its use.

Environmental considerations tend to be marginalised in the modern design process to the extent that Environmental Impact Statements have been introduced around the world in an effort to ensure that the environment is considered by those designing significant engineering projects. Yet whilst environmental impact statements may deal with the gross impacts of developments on the environment, the environmental considerations that should be considered at the design stage of every product and project of whatever size, such as the choice of materials, layout and processes and the implications that follow from these, remain neglected.

Environmental considerations need to be incorporated into engineering design in the same integral way that economic considerations are. As well as continually refining their designs to minimise use of materials, energy and labour engineers could also be refining their designs to fit into the environment harmoniously and with minimum disruption or degradation of natural ecosystems.

Sharon Beder is author of The New Engineer: Management and Professional Responsibility in a Changing World (Macmillan 1998) in which this argument is elaborated more fully.