Some years ago I was walking through an old Victorian house that was being renovated. In one room where the original wall framing was exposed, I found a curious bit of workmanship. One of the two-by-four studs had been carefully notched about halfway up, and a small hardwood wedge had been driven in. After a moment’s study, the reason became clear: the two-by-four had been badly bowed, and rather than cutting it up for some lesser purpose, the Victorian carpenter had used an age-old but effective trick to make it straight again. Then he’d installed the mended stud in the wall along with the rest.

Why all this effort to save a single stick of lumber? The answer demands some historical context. In Victorian times, labor was cheap, but building materials were not. Hence, a carpenter would think twice before tossing out a crooked two-by-four if a few minutes work could make it useable. The carpenter’s time, after all, was a trifling expense compared to the cost of that two-by-four.
Today, the situation is exactly reversed. Lumber and many other building materials are relative bargains compared to the cost of labor, which typically consumes at least two-thirds of the building budget. Hence, a modern-day carpenter wouldn’t bother fixing a crooked stud because, given his hourly wage, the time he spent would easily exceed the value of the lumber he was saving.
There’s no doubt that this situation often leads to unnecessary waste, because it’s ultimately cheaper to use extra material if it speeds up the work. For instance, a hefty 4-by-12  header is typically installed over windows and doors even when it’s structurally unnecessary, simply because it takes less time to install than numerous smaller pieces of lumber. 
On the bright side, though, escalating labor costs have actually forced the construction industry to become faster and more efficient. Among the earliest labor-savers were fully pre assembled windows, which arrived in the 1930s (previously, windows were built on site, either from stock parts or entirely from scratch). 
The construction exigencies of World War II spurred another great labor saver--gypsum wallboard. So-called “drywall” did away with the tedious process of wet plastering, which entailed nailing up thousands of feet of wooden lath, applying three separate coats of plaster, and waiting for days while each coat dried. 
After these developments came pre-hung doors, manufactured roof trusses, modular cabinets, and all the other prefabricated components so important to reducing onsite labor. There’s no doubt that mass-producing components in a purpose-built factory, immune from weather, dirt, and damage, is more efficient than building them onsite. The only downside is a subtle but unmistakable aesthetic change: As houses increasingly trend toward being mere assemblies of manufactured items, most of what meets the eye--windows, doors, cabinets--has the unvarying consistency you’d expect from mass-produced products. 
Hence, there’s less and less distinction among houses, and fewer and fewer traces of the individual prerogative that was a hallmark of hand craftsmanship. This, I suppose, is the price we pay--for the prices we’re paying.