Fax machines are almost as familiar as telephones in many big construction offices, and with good reason. The low operating cost of a fax machine often makes sending and receiving faxes the cheapest way to communicate for both routine and rush jobs. But fax machines are also a good fit for small builders. Their speed and convenience can help save a small contractor's most valuable asset — time. Fax (short for facsimile) transmission is a lot like photocopying by telephone. The sending fax machine digitally scans the document and transmits it electronically over the telephone lines. The receiving fax machine reverses the process and prints a copy of the original document. You Want It When? A fax machine's ability to deliver paper copies immediately