Colonial American homes are not so short ceilinged that the average person, even today, needs to watch their heads. Ducking in doorways isn't a big deal. Yes,

Colonial American homes are not so short ceilinged that the average person, even today, needs to watch their heads. Ducking in doorways isn't a big deal. Yes, standards for comfort were different back then but you don't see things get built that are actively hard to use unless there is some very serious thing you get from the tradeoff (like the deck heights in ships) because things need to be used to produce results. In a world where stuff is expensive and labor is cheap things get build such that the ability to apply labor to them is not a bottleneck. For example a work station that can be effectively operated by larger people tends to permit smaller people to work really fast without conflicting as much if the situation demands it. Some tool that operates by human muscle power and is just the right balance of mechanical advantage vs speed for the smallest man in normal conditions can be worked by a woman or child in ideal circumstances or a normal may may be able to work it for extended hours under normal conditions. Whether the tradeoffs make sense depends on the application.