Just a thought for you from ...

Just a thought for you from past experience.  When we installed our water treatment laboratory we looked at the specks. for both the one inch water line, water meter, and the back flow preventer.   The one inch water meter had the same flow rate as a 1.5 inch back flow preventer.  We installed ant 1.5 inch Backflow preventer to get a greater flow rate from the line.  The monthly fee for a 1.5 inch water meter is much greater than for a 1" meter.  

The water pressure at your location will also make a great difference in the flow rate.  We have greater than  100  psi pressure on the street which is reduced for the potable water use.  But for filling our tanks for production we can bypass the pressure regulator and shoot 100 psi straight to the back of the building on a 1.5 inch line coming through a 1" water meter.  The meter is still accurate at the higher pressure: it just sings when we start to fill 1300 gallons in a very short time. 

It all depends upon what you want to do.  Look at the specks for the incoming water line at the pressure it is delivered to you.  Larger pipes in your building can save you a lot of time.  Look at sizes, flow rates, and pressures. 

The plumbers could not, or would not, understand why a 1.5 inch Backflow preventer was being installed on a 1" line. We had to  carefully and respectfully explain several times: it was also in the building rehab plans and contract.  

Digging up the street to install a larger line would have been a waste of money: we charge our tanks two or three times  a month.  Instead, we installed larger lines and a 1.5 inch BF preventer on a 1 inch line.   The potable water section is still on a 1 inch line.