CalGreen Residential Baseline Water Reduction Calculator

2 Easy Steps To See If You Meet The 20% Water Reduction

CalGreen requires a twenty percent reduction in overall use of potable water within a building. To demonstrate the twenty percent reduction to the building water use baseline, the calculation must show a combined reduction for showerheads, lavatory faucets, water closets and urinals. The twenty percent reduction calculation is compared to the baseline water use calculation for only those same fixture types.

1 Number of
Bedrooms:
occupants: (Fixed result of bedrooms +1)

baseline calculations

This section calculates the baseline water usage for the home using the number of bedrooms entered above.

  Flow Rate
(in gallons per minute)
Duration
(in minutes)
Daily Uses Occupants GPD  
Showerhead 2.5 8 1      
Lav 2.2 0.25 3      
Water Closet 1.6 1 6      
        Total:    
      20% Reduction Target:    
         
step 2

20% Reduction

This section calculates your actual water usage when using water-efficient fixtures. 1.5 gpm has been entered for lav faucets.

Enter the flow rate for the showerheads and water closet below.
  Flow Rate
(in gallons per minute)
Duration
(in minutes)
Daily Uses Occupants GPD  
Showerhead 8 1      
Lav 1.5 0.25 3      
Water Closet 1 6      
        Total:    
    20% Reduction Achieved?    
    < Back Print Results