Can you tee off before the stop cock on the rising water main if there is
separate isolation provided?
I'd be very suprised if the answer was yes.
I probably don't want to do that, but it would improve performance to my
boiler with out ripping the kitchen apart, since All the new plumbing is
under the floor.
I guess I don't want to put another stopcock in the cellar.

This is the existing layout

|
|____
| |
x | x = accessible s.cock
| |
==========floor level===
| |
| |
| |______
| |
| |
^
m
a
i
n

TIA,
Mike W