Construction mystery

Let's see how much noise this makes

There is something unusual about the construction site next door, where they are probably trying to squeeze ten houses into a plot that used to house one.

At about 8 in the morning, when they are legally allowed to start banging about, they start banging about, hammering things here and there, dropping something that sounds like their hammer on something that sounds like a metal sheet floor, with several reverberating clangs.

Then at about 9 plus, the banging, hammering and clanging stops.

Does anyone in the construction industry know what’s going on? Especially in light of recent reports about the abysmal productivity rates?

Is it that the banging, hammering and clanging work is normally scheduled for between 8am and 9am? And then from 9am to 5pm, the workers either guide traffic or quietly meditate?