if your town allows the foundation to be just 2 feet deep and then rebar drilled into the bedrock to anchor the house. since there is no danger of frost heaving. do a 3 foot crawl space. in newfoundland if you have seen them houses on the hills, this is the method they use,as they can not blast over other houses. seen it on tv. forms were a pain to curve to the rock.

I came across a web site regarding a foundation system consisting of rigid foam sheets with plastic spacers holding them together.. the builder simply pours concrete in and the foam remains on the interior and exterior wall for insulation value.. it was suggested one could cut the sheets of foam to fit with the contour of the bedrock ensuring a seamless fit..

One possible solution..