From a reader:

Having spent 14 years as a residential carpenter, I find this whole Habitat thing silly. You end up with a bunch of well intentioned, but totally useless, people framing houses. They don’t even know the proper hammer (22 oz, framing hammer) to use for framing, don’t even know how to hold it (in a fist), don’t hit the nails hard enough – causing splits in the 2Xs.
Of course, carpenters hardly ever use hammers for framing and sheathing any more. THEY USE PNEUMATIC NAIL GUNS, allowing them to work 30 TIMES FASTER and never get sore arms, never get bent nails from bad hits, never get splits in the framing.
I guess that it looks good that these “caring” people are out there wasting time swinging hammers, but the fact is that nails guns would get the whole thing done in no time. But it wouldn’t be very good TV.