M Q wrote:

With sprinklers (I assume required by building code), the fire codes
and local fire authorities are going to tell you what size pipe
you need, what flow rate, and whether you need to sustain
that rate for just one or all three houses.

That was my thought also. I can't recall what the rule was right now, but I know
the code inspectors are pretty strict around here.

--
"Tell me what I should do, Annie."
"Stay. Here. Forever." - Life On Mars