I've never seen a glass coffee table come as part of a house construction, therefore it wouldn't be included in any type of building code. However, I do see wh

I've never seen a glass coffee table come as part of a house construction, therefore it wouldn't be included in any type of building code. However, I do see what you are trying to get at. The basic issue is what is the thresholds of affected people needed before something should be included in a public standard? If something is unusable for, say, 20% of the population, then it should be modified for inclusion. If it only affects .0000001% of the population, then it probably isn't worth worrying about. And cost / aesthetics / personal preferences should factor in, based on how many people are affected -- that is, the fewer that would benefit from an inclusion rule, the more other factors (such as cost, or design considerations, etc) should weigh in against inclusion. And if half the population is affected, then that would put more weight on inclusion and less on cost. Then there is the threshold of public buildings vs. new construction for private residences. As mentioned previously, the purpose of including residences in the inclusion laws (and actually all building codes) isn't for the current owner, but for the benefit of future owners and their visitors. Again, the percentage of the population that would benefit from a particular building code can weigh in on how much other factors are considered that would weigh in against the code. Which is why door handles are specified to be at a specific height, so that it is usable for the greatest range of the population. Of course, the whole door knob vs. lever thing can be retrofitted without changing the door hardware -- someone just needs to invent a clamp-on device that would add a lever to an existing knob.