Well, this is news to me about having to install underground piping that can never be serviced or inspected.
All the big buildings I work in have either cast Iron radiators or Cast Iron baseboard or scorched heating (heating ducts)
To pour concrete over a perfectly sound floor sounds like an engineer who has trouble sleeping at night and looking to think up things so the boredom will help him sleep.
I wonder what folks did in the OLD DAY like the early 60’s in Bowling allies to keep warm?
OH well why not just E mail me and ILL let you meet my team of experts on my list to answer you