Whether it's an insane, just-waiting-to-burst bubble or just what economists would call a healthy price signal, booming housing prices are being translated into building activity.

That’s real activity, not just a round-robin exchange of established homes for increasingly gobsmacking sums of money. It’s an actual pickup in the amount of building work being done, with all the job-creation and positive spillovers to other industries that come bundled with it. There was a taste of it…