We were called in to finish the network wiring in a construction project involving a beautiful house perched majestically overlooking a Toronto ravine. The last contractor and electricians had been fired, and drywall was complete. We could only hope that the raw data cabling was sufficient. In a new home, the slower Category 5e data cable was the wrong choice, and did not even meet the slower speed qualifications. This new construction project should have been minimum Category 6 to handle future needs.
But someone must have been thinking futuristically, since they thought that there was no need for coax cable to be installed. The day the owners moved in, they found they could not get Bell DSL internet service, so they had to resort to cable internet, but without any coax cable in the house, there was no way to get cable to the TV in the media room. It required a signal conversion system that cost as much as installing coax cable thoughout the house to solve the problem without cutting the newly finished drywall.
Low voltage data and A/V cabling is a specialty well beyond the capability of electricians, just as we do not mess with high voltage electrical. But it is essential to involve or consult an A/V integrator before construction begins, if only to be sure you are not going to run into staggering limitations.