What lengths and widths of wood can you buy from the lumberyard? What is the common width and thickness of drywall sheet you can buy and the hardware store? Wh

What lengths and widths of wood can you buy from the lumberyard? What is the common width and thickness of drywall sheet you can buy and the hardware store? What door sizes are available? What size of screws are cheaply available in Canada? I think these factors are far more likely to affect what unit of measure is commonly used in construction, rather than any intrinsic merit of the measurement system. If you were shopping at a Japanese or German hardware store, you'd probably suddenly find all of those 12 foot dimensions quite frustrating and not be at all surprised to find the hard-hat-wearing locals happily using the metric system for the same tasks.