I recently did an inspection on a 2 year old, 3 story townhome with copper plumbing. Water pressure at hose bibs was ~65 psig. The flow rate at the tub in the 2nd and 3rd floor bathrooms was just slightly > than 2 gpm. My understanding is that flow should be a least 4 gpm at bathtubs. Any suggestions on how this individual can get the flow increased to these areas?