[dj3]

In my area we branch all irrigation and outside hose bibbs off the main line before it enters the bldg, and install a separate shut off.
This way it's independent and has more pressure.
See if you can locate such a shut off. If not, install one.

 

[dj3]

To add: We do that because indoor pressure (50-80) may not be sufficient for your outdoor needs,

 

[dj3]

Lenaitch,
The meter is in the parkway (close to the curb).
From the meter we have one main to the house. 3/4" or 1" copper, about 12"-15" deep.
It rises up near the house and we split it to two: One to the house and one to the sprinkler system and each one of them gets a shut off valve and a pressure reducing valve.
I set the PRV to the yard at 80 psi or higher. The PRV to the house between 50-80 psi.