This doesn't happen to me often enough and, unfortunately, this is not my client. I have been following the process of a house being built in Northern VT on the blog Building Green in Vermont They had been working with a designer and had come up with a rather large and boring house (in my opinion) then this happened:

And the bids we received for materials like siding, roofing, windows, etc. were higher than we could really afford. It became clear that the best thing to do was reduce the size of the house.

The more we thought about the prospect, the more excited we got. We are all about going green and yet we missed the most obvious strategy of all...reduce the building's footprint. In addition to cutting the materials needed for construction and thus saving resources, a smaller house means lower energy usage. It also means disrupting a smaller part of the site.

I think they went from 2160 square feet down to 1568, ended up with a much nicer house that any realtor worth his job would tell you they could sell quicker and for more if given the chance. I expect the owners would never give a realtor that chance. this is what they ended up with