I'm a longstanding dev and also have a keen interest in housing. I've designed a passive solar house & known a lot of builders. The idea that architects specify things to the millimetre and implement from a finished, grand design will have the average builder rolling with laughter.
Yes, sometimes some elements are specified that closely. A surprising/terrifying amount is worked out on the job, between different levels of the building professionals.
(re-read for the umpteenth comforting time)
Poesy words arrive
in my whisky’d dog-woken brain,
like ant-trails of rain
on drought-set clay.
Blinkingly real,
tears of electric, distant storms.
Zelazny wrote,
of moth-made, Vorpal sword,
lines to end all…