First of all I agree completely with the major part of your story and I enjoyed a lot the description of the workshop discussions. However I am not quite happy with your introduction. Though it gives a nice analogy of things which really also can happen in engineering design efforts for detectors and accelerators, I fear it somehow transports the wrong message. One could get the impression that the ILC physicists live in their dream world designing unrealistic and expensive detectors without taking care of the engineering and financial reality.

The detector concepts under study have undergone several steps of realistic engineering. Most of the concepts have also done engineering studies on detector halls which in some cases were much more detailed and on higher engineering design level than the common ILC detector hall is now.

The major reasoning behind IRENG was, that we all (machine and detector people) have to tackle together a new problem which has never been tried before, i.e. the push-pull approach. And this problem really requires a joined effort, which IRENG was a beautiful example of.

-- Karsten Buesser, DESY