Estidama tool

Estidama Water Reduction (PW-R1 / PW-1)

Enter the quantity of each fixture and the flow rate of the model you actually specified. The tool compares the design daily volume against the baseline and returns the reduction achieved.

🧪 Example figures

Illustrative only — not typical values, not a recommendation. Replace with your own.

↳ Three rows sit AT the baseline and claim nothing — PBRS’s urinal and public-tap figures are aggressive and most catalogue models do not beat them.

📋 PW-R1 requires predicted consumption to be no greater than the baseline. It awards no points.

Fixture	Baseline	Durationassumption	Uses/dayassumption
Water Closet (Dual Flush)	6 L/flush6/4 liters/flushing cycle (full/low)	1	3
Urinal (Commercial)	0.5 L/flush0.5 liters/flushing cycle	1	2
Lavatory Faucet (Private)	6 L/min6 liters/min at 417.7 kPa	0.25	3
Lavatory Faucet (Public)	1.9 L/min1.9 liters/min at 417.7 kPa	0.25	3
Kitchen Sink	6 L/min6 liters/min at 417.7 kPa	1	1
Shower Head	9.5 L/min9.5 liters/min at 551.6 kPa	5	1
Bidet	6 L/min6 liters/min	0.25	2

Water Closet (Dual Flush): The standard publishes a pair (full/low). The blend ratio between them comes from the authority's own calculator, so this tool uses the full-flush figure, which is the more conservative of the two.

Design flow must come from the manufacturer datasheet for the specified model — not a typical value.

Result

21.5%

✓ At or below the baseline

PW-R1 requires predicted consumption to be no greater than the baseline. It awards no points.

Baseline daily volume: 474.3 L/day
Design daily volume: 372.3 L/day
Saved per day: 102 L/day

📄

PW-R1 requires the authority’s own Building Water Calculator to be submitted, together with fixture specifications and a water-strategy narrative. This tool is a preliminary estimate for design decisions — it is not that submission and does not replace it.

Frequency and duration are editable assumptions, not published values — PBRS defers them to the authority’s Building Water Calculator. Change them to your project’s occupancy.

Source

Pearl Building Rating System (PBRS): Design & Construction, Version 1.0, April 2010 — credit PW-R1, page 118 of 223, published by the Department of Municipalities and Transport (DMT). Baseline flow rates only; usage frequency and occupancy are not published in the document and are deferred to the official Building Water Calculator.

This calculator applies the baselines it was given and the formula in the brief. The credit itself is awarded by the authority against the rating system edition in force; nothing here is an approval.