You can't just say "80% is wasted" when it's just wood that is used for other purposes than timber. Until we can convince Mother Nature to grow trees which are perfectly straight and preferably already square, the process of converting a cylindrical log to a square beam will inherently have some cutoffs.

The linked article in turn links to a research paper at https://www.woodresearch.sk/wr/201202/12.pdf, and while that paper does support that only ~20% of a tree gets sawn into long pieces of (construction) lumber, it absolutely does not support that the remaining 80% is waste. For example, ~37+9= 46% goes to the production of chip and particle boards, a decent amount becomes firewood, the paper industry takes some "waste" wood as input for cellulose production, sawdust has a variety of purposes and even the leaves and stumps can simply be composted.

It's mind-blowing because it is bullshit and a total misrepresentation of the paper it cites. What the paper says is that less than 20% of the volume of the tree (including the branches and the leaves and the stump) becomes dimensional lumber, 40% becomes chipboard, 7% is firewood, 2.3% is sawdust, and the remainder is burned.

Any time you find yourself surprised by a claim, that's your signal to dig into the sources.

Not to say there's nothing wrong with modern construction, but keep in mind that most roman buildings also only lasted a few decades. You only see that ones that didn't disappear.

Also, do we really want to build houses that are meant to last 2000 years? It seems expensive and very impractical when you want to tear it down to build something new.

I don’t know if that is the right approach. While I am sure fashions changed in Ancient Rome, I am not sure how fast the pace of innovation was. Within a hundred years modern building techniques have changed massively. I know certain Europeans always love to tout their stone homes but for lots of the world it’s not very practical or cost effective.

Or at least have buildings be easily reconfigurable.

Those Roman buildings are not what you want to live in. Just adding electric lights which you want is going to be a major effort and likely ruin a lot of what made it a nice building in the day. Not to mention you want indoor plumbing (without the lead pipes). Modern insulation so you can have modern HVAC...

The vibe this stuff gives off to me is the "environmentally friendly" materials racket wherein some jerks lobby for some public/private rule/requirement change that's favorable to some product on the basis of the environment and that product is only marginally better for the environment (usually because it takes a recycled thing as one of its inputs) while being substantially more expensive/less performant per dollar. But the people pushing for the change don't care because are or are paid by the people who make the new thing that wouldn't have seen serious adoption without the change favorable to it.

I've seen plenty of people sleeping rough without tents on the street. Not everyone can afford a tent - some sleep alone, some drag a mattress or sleeping bag around and try to find spots to use.

Those drywall sheets generally won't be in good enough condition to reuse. Insurance concerns over possible mold infection make this a non-starter.

Removing drywall sheets for reuse is basically impossible. There’s a couple dozen screws holding each piece of drywall in place and they’re not easily removable without damaging the drywall.

In general, salvaging material from construction demolition isn’t worth the time, with some exceptions like copper. The metal and concrete will be recycled, everything else is garbage.