Today I had the first opportunity to go into the crawl space and take a close look around. The space is relatively clean and with a little bit of effort can be made into a very tight envelope.
I have been disappointed with the water pressure since we moved in. In the crawl space I found the incoming 3/4" galvanized supply line. The supply line transitions to copper at an elbow just inside the foundation wall. A 1/2" line tees off to the hose bibb on the front of the house before the main line continues to the PRV.
I put a gauge on the hose bibb on the rear of the house and it read 40 psi. This hose bibb is downstream of the PRV. Then I walked around to the front of the house and put the gauge on the front hose bibb that is before the PRV, it read 70 psi.
I was happy to see that we had much more pressure available so I adjusted the PRV to give us around 60 psi. It made a noticeable improvement with the water pressure in the house. The fixtures are much happier now.