Increasing density in urban areas by building up is the right thing to do, compared to expanding urban areas which would require more paving, more roads, and more inefficient use of land.

It's the way we design those new buildings that's important.

Increased density means fewer low density buildings and paved surfaces elsewhere. Urbanization is a massive net positive for the environment.

It's a lot easier to insulate multi story buildings. Volume grows faster than surface area.

You're just trading off energy spent cooling denser cities vs. increased transportation in less dense cities.

Why is that bad? people complain about the enormous costs of accommodation, to which the main solution is simply to build more.

Your proposed alternative is to increase urban sprawl?

What? No. My point is that each new building is a chance to do better. Claiming it’s too late because we have built up areas is helplessness.

If you double the size of a town and build the new half well you solve more than half of the problem.