Part G Water Efficiency Calculator

Part G Water Efficiency Formula:

\[ lppd = \frac{\sum (F_i \times U_i)}{O} \]

Occupancy (O):

persons

Toilet Fittings (F_i):

units

Toilet Usage Rate (U_i):

l/day

Shower Fittings (F_i):

units

Shower Usage Rate (U_i):

l/day

Tap Fittings (F_i):

units

Tap Usage Rate (U_i):

l/day

Water Consumption (lppd):

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1. What is Part G Water Efficiency Calculation?

The Part G Water Efficiency calculation determines the average daily water consumption per person in liters per person per day (lppd) according to UK Building Regulations Part G. This calculation helps ensure buildings meet water efficiency standards.

2. How Does the Calculator Work?

The calculator uses the Part G water efficiency formula:

\[ lppd = \frac{\sum (F_i \times U_i)}{O} \]

Where:

\( lppd \) — Liters per person per day
\( F_i \) — Number of fittings of type i
\( U_i \) — Usage rate of fitting i (l/day)
\( O \) — Occupancy (number of persons)

Explanation: The equation calculates the average water consumption by summing the total water usage from all fittings and dividing by the number of occupants.

3. Importance of Water Efficiency Calculation

Details: Water efficiency calculations are crucial for compliance with UK Building Regulations, promoting sustainable water usage, reducing environmental impact, and ensuring adequate water supply for building occupants.

4. Using the Calculator

Tips: Enter the number of occupants, count of each type of water fitting (toilets, showers, taps), and their respective usage rates. All values must be valid (occupancy > 0, fitting counts ≥ 0, usage rates ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: What is the maximum allowable lppd under Part G?
A: The maximum allowable under Part G is 125 liters per person per day for new dwellings.

Q2: What are typical usage rates for different fittings?
A: Typical usage rates: toilets 6 l/day, showers 35 l/day, taps 8 l/day, but these may vary based on specific fitting types.

Q3: How is occupancy determined?
A: Occupancy is typically based on the number of bedrooms, with standard assumptions of 2 persons per bedroom.

Q4: Are there different requirements for commercial buildings?
A: Yes, commercial buildings have different water efficiency requirements and calculation methods under Part G.

Q5: What if my calculation exceeds the maximum allowable?
A: If the calculation exceeds 125 lppd, water-saving measures such as low-flow fittings or rainwater harvesting may be required.