According to dpb :

What are standard building dimensions as compared to US? Here, framing
is 16" OC so virtually all sheathing materials are 4' x 8' which is
both a convenient size for handling and works out evenly in both
directions. The "tubafor" has evolved over the years from being a
rough (green) sawn actual 2" x 4" through various finished sizes to the
now familiar 1.5" x 3.5". Precut studs are made for base and top
plates to end up w/ finished wall heights of 8' which accomodates 4'
wallboard w/o trimming. I've never built anything outside the US but w/
all the trade between the two and general dimensions of buildings there
certainly aren't far different than ours, I presume there's
considerable overlap?

It's a trick of proportion. We average twice as tall as you guys,
so the building standards are based on entirely different numbers.

snicker ;-

In reality, Canada has evolved to a situation somewhat short of
where Europe is. All official weights and measures are MKS (metric),
such as surveys, standards etc. Schools teach very little of FPS
(Imperial aka "english"). The latest generation can pretty much
entirely avoid FPS until they're in the construction industry.

Residential construction _itself_ is still using an unchanged system
almost identical to yours. 2x4s, 8x2 sheets of construction plywood,
12/16/24" joist spacing etc. We do see sheet goods with metric
thickness measurements (eg: 11mm sheathing), and the odd bit of
sheet goods (normally not for construction) with metric dimensions -
eg: furniture grade plywoods or melamine - about an inch oversize.

It may seem confusing, but in practise it isn't.

I grew up in FPS, and now I'm equally comfortable in both systems.
[Except pascals. I hate pascals. They should use mm of mercury -
that I can visualize - it's been around far longer than our metric
"conversion".]

Given the education system, and another generation, only a few
industries will be doing much in the way of FPS, and we'll arrive
in a situation where we'll be viewing construction practise in the
same way you should be viewing that idiotic penny nail measurement
"standard".
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.