They say it is because of new valves they had to put in due to New codes. However, our house is only 2 yrs old so nothing has changed regarding codes and the water pressure is significantly less than what itvusee to be and what the other shower in our house is. The shower is beautiful and the person who installed it was courteous and dud a good job other than the water pressure issue. Unfortunately, we will have to put up with low pressure and that erases all the good things about our new shower.