[spqr0a1]

This is the basis for customary nail sizes, as it's (for example) how many 6d nails you could get for 6 pennies in medieval England. https://en.wikipedia.org/wiki/Penny_(unit)

[monkeycantype]

I'm of the opinion - though not 100% confident - that you can tell the difference between houses built with metric and imperial materials.

I think you can perceive the different factor relationship between the dimensions of timber, fittings and spacing. Although I'm not entirely certain that I'm not picking up other cultural habits in Australian and American building styles. Should I ever ascend the throne, I shall have an imperial palace (naturally) and a metric one built to the same plan to verify my intuition

[InitialLastName]

With CAD being what it is, if you have them built to the same plan the engineers will just convert with fairly good precision. What you need is a metric architect and an imperial architect to do plans based on the drawing of a pre-numerate child or (better) a tasteful adult from a culture without measurement units who won't have internalized the visual languages of metric or imperial ratios.

edit: Words are hard

[monkeycantype]

> pre-numerate child or (better) a tasteful adult

my two favourite moments in a documentary are #1 in 'the smashing machine' when you glimpse a the boot of the bad girlfriend in the corner, and feel before you know that everything is about to go bad

and #2 in the documentary 'Jean Nouvel: Reflections' about the architect of the same name, where you see him at work, in a dark cozy restaurant at a table surrounded by staff/devotees swirling a full glass of red wine, and he's looping loose enigmatic squiggles on wine stained napkins which he then passes out, a sacred relic, one to each person at the table. And off they go and make the buildings that bear his name.