# Greywater System Installation Cost Calculator & Price Guide

This is the text version of https://www.supertrades.com.au/calculators/greywater-system-installation-cost-calculator.

Use this guide to estimate grey water system cost, grey water installation cost and the cost of installing a greywater system for your home. In Australia, supply and install pricing typically starts at about $1,500 AUD for a basic gravity diversion setup and can reach around $6,500 AUD for a treatment system before access or trenching multipliers are applied.

## Greywater System Installation price breakdown

Typical job based on 1 system (Short irrigation run, easy plumbing access). Prices are supply-and-install midpoints. Actual quotes vary.

| Type | Cost per system (Short irrigation run, easy plumbing access) | Typical 1 system (Short irrigation run, easy plumbing access) job |
| --- | --- | --- |
| Gravity diversion (garden irrigation) | $1,500 | $1,500 |
| Pumped diversion (sump + pump) | $2,800 | $2,800 |
| Treatment system (higher reuse) | $6,500 | $6,500 |

## What affects Greywater System Installation cost

- **System type:** The biggest driver of price is the type of system you choose. A gravity diversion system is $1,500 AUD per system, a pumped diversion system is $2,800 AUD, and a treatment system is $6,500 AUD at the base short-run, easy-access rate.
- **Irrigation run length and trenching:** If the greywater needs to travel further to reach the garden, extra trenching and pipework increase costs. The pricing multiplier for longer irrigation or more trenching is ×1.25.
- **Plumbing access and slab constraints:** Jobs are more expensive when plumbers have hard access, need to work around slab construction, or face difficult connection points. Hard plumbing access or slab constraints use a ×1.45 multiplier.
- **Number of systems:** This calculator is priced per system, so adding more systems increases the total in direct proportion. The estimate also applies a ±15% range around the midpoint, with a minimum job charge of $900 AUD if calculations fall below that level.

## Frequently asked questions

### What is the typical grey water system cost in Australia?

For 1 system at the base short irrigation run and easy plumbing access rate, a gravity diversion system is $1,500 AUD, a pumped diversion system is $2,800 AUD, and a treatment system is $6,500 AUD. The displayed estimate range is usually shown at ±15% around those midpoints. That means the final displayed range can vary depending on the system type you select.

### How much is the grey water installation cost for a gravity diversion setup?

A gravity diversion system costs $1,500 AUD per system for supply and install at the short irrigation run, easy plumbing access setting. If the job needs longer irrigation or more trenching, apply the ×1.25 multiplier. If access is difficult or there are slab constraints, apply the ×1.45 multiplier instead.

### What affects the cost of installing grey water system plumbing and irrigation?

The main cost factors are the system type, how far the irrigation run needs to go, and how easy the plumbing is to access. Base prices are $1,500 AUD for gravity diversion, $2,800 AUD for pumped diversion, and $6,500 AUD for treatment systems. Longer irrigation uses a ×1.25 multiplier, while hard plumbing access or slab constraints use ×1.45.

### What is the greywater irrigation system cost if the run is longer?

A longer irrigation run increases the base system price by ×1.25. For 1 system, that takes a gravity diversion setup from $1,500 AUD to $1,875 AUD, a pumped diversion from $2,800 AUD to $3,500 AUD, and a treatment system from $6,500 AUD to $8,125 AUD before the ±15% displayed range is applied.

### How much does the cost of installing a greywater system increase with hard access?

Hard plumbing access or slab constraints increase the base rate by ×1.45. For 1 system, that changes a gravity diversion system from $1,500 AUD to $2,175 AUD, a pumped diversion system from $2,800 AUD to $4,060 AUD, and a treatment system from $6,500 AUD to $9,425 AUD before the estimate range is shown.

### Can I use this calculator for a full grey water setup estimate?

Yes ,  the calculator is designed around the number of systems, with 1 system as the typical job example. It starts from the supply-and-install base prices of $1,500 AUD, $2,800 AUD, or $6,500 AUD depending on the setup you choose, then adjusts for longer irrigation or harder plumbing access. If any calculation falls below the minimum job charge, the estimate will default to $900 AUD.

Quotes: [Greywater System Installation](https://www.supertrades.com.au/greywater-system-installation/index.md).