Calculator

Start your calculation

To start your calculation please select which criteria from the list below you want your project to meet.

Maximum consumption of potable water (litres / person / day)
 
125
110
Your own defined level

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Please suppy a Maximum consumption of potable water (litres / person / day)

Add data to your calculation

Click on the small icons by the installation type to add data for that product to your calculation

Project Name

*New buildings must have at least a toilet, washroom taps, a bath or shower, and kitchen taps.

 
Installation Type
Unit of measure
Capacity / flow rate
Use Factor
Fixed Use
Litres / person / day
*Toilet (single flush)
Flush volume (litres)
4.42
0.00

Please select your Single flush Toilets from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Single flush toilet
Flush volume
(litres)
Qty
Total
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Average Flush volume (litres)
Add to Calculation
*Toilet (dual flush)
Average effective flushing volume (litres)
1.46
0.00

Please select your Dual flush toilets from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Dual flush toilet
Flush volume
(litres)
Qty
Total
add row
remove add row
remove add row
remove
Average Flush volume (litres)
Add to Calculation
*Taps including Basin & Bidet
Flow rate (litres/minute)
1.58
1.58

Please select your Taps (excluding kitchen/utility room taps, bath/shower taps, and external taps) from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Tap
Flow Rate
(litres)
Qty
Total
add row
remove add row
remove add row
remove
Average Flow Rate (litres)
Add to Calculation
*Bath (only)
Capacity to overflow (litres)
0.11
0.00

Please select your Bath from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Bath
Flow Rate
(litres)
Qty
Total
add row
remove add row
remove add row
remove
Average Flow Rate (litres)
Add to Calculation
*Shower (only)
Flow rate (litres / minute)
4.37
0.00

Please select your Shower from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Shower
Flow Rate
(litres)
Qty
Total
add row
remove add row
remove add row
remove
Average Flow Rate (litres)
Add to Calculation
*Kitchen taps
Flow rate (litres / minute)
0.44
10.36

Please select your Kitchen taps from the drop-down lists on the left.
Once you have made your selections, click the 'Add to calculation' button to add the data into the main calculation table.

Brand
Efficiency Rating:
Kitchen sink taps
Flow Rate
(litres)
Qty
Total
add row
remove add row
remove add row
remove
Average Flow Rate (litres)
Add to Calculation
 
Washing machine
Litres / kg dry load
2.1
0.00
 
Dishwasher
Litres / place setting
3.6
0.00
 
Waste disposal unit
Litres / use
3.08
0.00
 
Water softener
Litres / person / day
1.00
0.00
Contribution from Grey Water
Bath, shower, and hand basin usage (l/p/d)
Percentage of used water to be recycled (%)
Greywater available for use (litres/person/day)
Greywater demand (litres/person/day)
Greywater savings (litres/person/day)
Add to Calculation
Contribution from Rain Water
Collection area (m2)
Yield co-efficient and hydraulic efficiency
Rainfall (average mm/year)
Daily rainwater collection (litres)
Percentage collected (%)
Number of occupants
Daily rainwater per person (litres)
Rainwater demand (litres/person/day)
Rainwater savings (litres/person/day)
Add to Calculation

* BS 8515 intermediate approach.

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Calculate
New buildings must have at least a toilet, washroom taps, a bath or shower, and kitchen taps.

Your target maximum consumption of potable water is 110 litres per person per day.

Totals

Total Calculated use (litres/person/day)
0
Contribution from greywater (litres/person/day)
0
Contribution from rainwater (litres/person/day)
0
Normalisation factor
0.91
Total internal water consumption (litres/person/day)
0
External water use
0
Total water consumption (Building Regulation 17.K)
0
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