The pipes bursting in air, gave proof through the night, that's it's still cold out there

The building I work in was closed today because the heating system wasn't able to keep the building warm enough to prevent pipe breaks without shutting down the fresh air ventilation system and losing heat out the doors.

This building has plenty of energy-saving features, but that doesn't help if the heating system is sized for typical and some excursion loads (but not the current extreme cold). That's because sizing a heating system for those rare events where you have extreme cold means wasting a lot of energy on a regular basis.

So, it may not be a lack of insulation but a lack of heating capacity given the insistence on keeping the building open - there is no way to "insulate" doors that open in such a way to move large numbers of people in and out, or insulate the need for fresh air in areas occupied by a large number of humans.

I design P/FP systems. The pipes themselves should have 1" of insulation (typ.) - domestic supply/return, mechanical supply/return and fire protection.

Also, your comment about ACT grid systems doesn't really hold up. The ACT grid is under the roof (or floor slab if there are floors above). The P/FP is typically above the ACT grid ceiling (where one is present and the system is horizontally distributed). There should be insulation in the actual building envelope - on the roof membrane as well as in the facade. That is what is truly insulating the cavities/interstitial MEP spaces from outside temperatures. This isn't quite enough insulation (especially in extreme temperatures), so we insulate the pipes themselves.

I'm generally frustrated at the economics of commercial buildings. The builder loses money to make buildings more efficient when its not a priority for tenants when other factors like location for neighborhood prestige, customers and workers, lease cost and terms, appearance, proximity to transportation, ease of permitting etc. are all often bigger factors than heating/cooling costs or greenness.

We simply don't hear of many occupied houses bursting water pipes like we do for commercial buildings in cold weather, so what's the conclusion to draw from that? Commercial buildings are less well insulated than private residential ones. Some condo and apartment complexes are built on the cheap and they also have pipe bursts just like commercial buildings built on the cheap. Again, the builder would lose profit making them more energy efficient.