My water preasure (new house) seems OK for normal things, showers, sinks, appliances but there is not enough pressure to push small sprinkler zone, bath tub has very low out put, hose very low out put, anything that uses a large amount of water. If these are turned on the sinks and appliances reduce a great deal, can barely get water from frig door. I can flush the toilet with no affect on shower. The plumber has moved the sprinkler to the street side of the house regulator, this did not help. No other houses around me have this problem. Gauge hooked to spicket or water heater says 67psi, If you turn on the sprinkler, tub or kitchen sink pressure drops to 35-40psi. Most people suggest kink or clog in main water supply, if so how can I determine this without digging this all up? Any other suggestions what could cause this.

My water preasure (new house) seems ok for normal things, showers, sinks, appliances but there is not enough pressure to push small sprinkler zone, bath tub has very low out put, hose very low out put, anything that uses a large amount of water. If these are turned on the sinks and appliances reduce a great deal, can barely get water from frig door. I can flush the toilet with no affect on shower. The plumber has moved the sprinkler to the street side of the house regulator, this did not help. No other houses around me have this problem. Gauge hooked to spicket or water heater says 67psi, If you turn on the sprinkler, tub or kitchen sink pressure drops to 35-40psi. Most people suggest kink or clog in main water supply, if so how can I determine this without digging this all up? Any other suggestions what could cause this.
... city water or your own well/pump? A water pressure drop of 50% may be significant enough to warrant a visit by your water utility.

It sounds to me like there is a restriction before the regulator since moving the sprinkler didn't help. Is the water meter at the curb? If so, beat on the builder. He is responcible for the piping from it to the house.