Front Matter

Ten years ago there were a few universities researching the possibilities of additive construction (AC). Five years ago there were half a dozen universities, some companies, and a small number of government laboratories exploring if there was any benefit to using AC. Three years ago there were a handful of demonstration structures, buildings, and bridges that were constructed using this technology. Today there are a dozen companies printing structures or providing printers for structures, a dozen design firms, two dozen universities, and a number of government agencies working on projects that utilize AC technologies.