Lol, you're right, it's not...but I'm in the age bracket that grew up learning the English system. I was already in my teens when they began to install the necessary clamps and brackets that held my mouth open to force-feed me the metric system. Growing up right on the border, exposed to mostly 'Murican TV, made me and my cohorts even more resistant to metric.
And, regardless of how indignantly self-righteous Canada likes to behave about being metric...we still buy plywood in 4x8-foot sheets, lumber and building materials are still sold in lengths of feet, housing and real estate is still usually described in terms of square feet and acres, eggs come by the dozen. All sorts of exceptions to the metric rule; I still "think" in English and have gotten fast at doing the necessary calculations to communicate with the New Age Canucks who surround me.
You'll note that the ruler...the yardstick...in my pic is in English only; no dual-marking crap if I can help it.
Well it doesn't surprise me at all that building materials haven't changed, and perhaps never will. It's been years since I visited your lovely country but the only differences 20 years ago we're the litres of gas and km signs on the road. Food was still in lbs and oz, and the casino let you in at 19. That's about all I remember, and we're pretty far from the OP subject now lol.