My experience here in Italy is limited to few not-so-small projects, and from my experience I doubt that a contractor (and I wasn't thinking about an individual

My experience here in Italy is limited to few not-so-small projects, and from my experience I doubt that a contractor (and I wasn't thinking about an individual, but a company that 99% of the times is led by salesmen) would even think about touching a volunteer with a 10 feet pole. But I'm glad to know this is not true in other parts of the world :) From what you said, a really nice idea could be to think about a process with which an administration could match volunteers with contractors... and then create an open source tool to facilitate that.