  Design mining is the use of computational intelligence techniques to
iteratively search and model the attribute space of physical objects evaluated
directly through rapid prototyping to meet given objectives. It enables the
exploitation of novel materials and processes without formal models or complex
simulation. In this paper, we focus upon the coevolutionary nature of the
design process when it is decomposed into concurrent sub-design threads due to
the overall complexity of the task. Using an abstract, tuneable model of
coevolution we consider strategies to sample sub-thread designs for whole
system testing and how best to construct and use surrogate models within the
coevolutionary scenario. Drawing on our findings, the paper then describes the
effective design of an array of six heterogeneous vertical-axis wind turbines.
