Household Pressure

My house is 2 years old, the builder installed the front sprinkler system so I was going to finally do the back. Everything said to check water pressure first so I did. The reading at a regulated extrior hose bibb (tapped right next to the current line to the front sprinkler) showes 80lbs. Checked with the city all they say is it needs to be below 80.

What is normal? We have a larger house (3 kids) so did the builder run it up high to adjust for possible complaints? What is a "normal" range?

I wouldn't worry about that pressure. You wouldn't want it any higher though.

The high pressure is fine for the sprinklers, but a bit high for the house. If it was mine, I'd install a pressure regulator inside the house before anything else takes off of the line. I'd set the inside pressure to about 60 psi. This will also require an expansion tank since the PRV will create a closed system. The expansion tank is place anywhere between the PRV and the first branch, especially before the water heater. Hot water expands and needs someplace to go. The PRV stops it from being absorbed by the city water main, so the result is you TP valve on the water heater will trip. Simple and inexpensive cure. High pressure does not equal high volume.

You will use more water at 80# than 60#. I set my customers pressure to 60# unless they want something different