Book excerpt: Building Systems Magazine (BSM) is an award winning United States-based trade magazine read by builders, developers and general contractors using or considering using innovative construction technologies. Once commonly known as "pre-fab," today's modern building systems employ innovative materials and techniques to create residential or commercial structures in a factory setting in a fraction of the time it takes to site build. BSM focuses mainly on log, timber frame, modular, panel, and structural insulated panel building technologies. Since factory fabrication and site preparation take place simultaneously, structures are finished and ready for occupancy in weeks, rather than months or years as required by conventional site-building schedules.