An average house does not take a year to build. Assuming the video was talking about all levels, a 4000 sqft would take a 4 man crew about 3-5 weeks to go from foundation to siding and shingles. What the concrete frame of a house doesn't account for is the need for a cavity for utilities to go through. Someone still has to go through the interior and frame with wood to allow for plumbing, electrical, and hvac. A smaller simple house can be done even quicker. My brother's house with a main level of about 1700 sqft was started on a Monday and painted the following Saturday with driveway, patio, and sidewalk all poured.