We argue that considering only a few ‘big’ ethical decisions in any engineering design process — both in education and practice — only reinforces the mistaken idea of engineering design as a series of independent sub-problems. Using data collected in engineering design organisations over a seven year period, we show how an ethical component to engineering decisions is much more pervasive. We distinguish three types of ethical justification for engineering decisions: (1) consequential, (2) deontological or non-consequential, and (3) virtue-based. We (...) find that although there is some evidence for engineering designers as ‘classic’ consequentialists, a more egocentric consequentialism would appear more fitting. We also explain how the idea of a ‘folk ethics’ — a justification in the second category that consciously weighs one thing with another — fits with the idea of the engineering design process as social negotiation rather than as technological progress. (shrink)